I chose by three things, the cooling rating, weight and price, with the eye of a fishing instructor who has fished for 30 years and holds a boat license. No. 1 is the Shimano Unifreeze BS 20L. It has urethane insulation and COOL90 at a list price of JPY 18,300 (excl. tax), and JPY 203 per hour of rated cooling is the lowest number of the five. I put the Fixell BS 22L, released in July 2026, at No. 3.
The Gear Nerd's Pick
The cooling number of a cooler is not the time measured until the ice melted. It is a value stretched by calculation, to the time it would reach 0%, from the ice left after 8 hours in a 40°C room. So before the size of the number, I check which scale it is on, and only divide price within the same scale.
Key points
- Daiwa's KEEP and Shimano's COOL have the same wording in their official method description
- The No. 1 Unifreeze BS 20L is JPY 203 per 1 hour of rated cooling
- Freega's I-CE is on a different scale; do not compare it alongside COOL
KEEP70 does not mean "it lasts 70 hours"
The number is a calculation. Both Daiwa's KEEP and Shimano's COOL are values from placing cube ice at 25% of the capacity in a 40°C room and calculating the "time until it all melts" from how the ice shrinks. It is different from actual cooling time.
On top of that, Shimano still has another scale, I-CE. It is confusing. To choose a 20L cooler by numbers, you first have to line up the scale.
How I chose
First I checked the scale of the cooling number. Next, within the five on the same scale, I divided the list price by the rating to get the price per hour.
I hesitated over the Fixell released in July 2026. It is new and the lid can be taken off from both sides, but per hour it costs JPY 100 or more over No. 1. So it is No. 3. I ranked these from the current models you can buy on Rakuten, looking at the official numbers.
Image: Rakuten Ichiba
Shimano Unifreeze BS 20L ND-620Y
Lowest price on Rakuten: JPY 13,294 (as of Oct 14). Some stores go up to JPY 19,138. Prices change daily.
RecommendedSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanWhat to look at when choosing a 20L fishing cooler
- For the cooling number, look at the name of the scale first. KEEP and COOL have the same description; I-CE is different
- Insulation: urethane, polystyrene (Styrofoam) or a vacuum panel. Within the same series, the difference in numbers shows as it is
- Look at weight on the assumption that you carry it full. Even around 20L there is a spread of 3.0–5.1kg
I weighted the first most heavily. If you skip it, you end up lining up numbers from different scales.
Quick table of five 20L fishing cooler models and one out of the ranking
Swipe the table sideways →
| Rank / model | Cooling rating | Insulation | Weight | List price |
|---|---|---|---|---|
| No. 1 Shimano Unifreeze BS 20L | COOL90 | Foamed urethane | 4.2kg | JPY 18,300 |
| No. 2 Shimano Unifreeze LT 20L | COOL70 | Expanded polystyrene | 3.8kg | JPY 14,900 |
| No. 3 Shimano Fixell BS 22L | COOL80 | Foamed urethane | 4.2kg | JPY 25,500 |
| No. 4 Daiwa Cool Line α III GU2000 | KEEP51 | Urethane | 4.0kg | JPY 17,600 |
| No. 5 Daiwa PV-REX GU2200 | KEEP70 | Urethane | 5.1kg | JPY 25,400 |
| Out of the ranking: Shimano Freega Basis 200 | I-CE 35h | One bottom face with a vacuum panel + expanded polystyrene | 3.0kg | JPY 18,000 |
The difference between KEEP, COOL and I-CE
Daiwa's KEEP is the time until the ice is all melted, converted from the remaining-ice rate calculated by the simple method of JIS S 2048. Shimano's COOL uses the same procedure, with 40°C outside air and 25% cube ice. Shimano calls it a "new cooling standard" and adds that it is a guide value from the company's own test.
The Unifreeze page says existing coolers use the I-CE notation. I-CE is a different scale from COOL, so I put the Freega out of the ranking and left it out of the division.
Price per hour of rated cooling
| Model | List price ÷ cooling rating | Per hour |
|---|---|---|
| Unifreeze BS 20L | 18,300 ÷ 90 | JPY 203 |
| Unifreeze LT 20L | 14,900 ÷ 70 | JPY 213 |
| Fixell BS 22L | 25,500 ÷ 80 | JPY 319 |
| Cool Line α III GU2000 | 17,600 ÷ 51 | JPY 345 |
| PV-REX GU2200 | 25,400 ÷ 70 | JPY 363 |
What surprised me is that the Unifreeze BS and the Cool Line α III GU2000, both urethane and both 20L, are 39 apart in the number. The wording of the procedure is the same, but each maker did its own measuring. So I discount differences across companies compared with differences within the same series. I write that honestly here.
Why this order
| Rank | Model | Reason for this rank |
|---|---|---|
| No. 1 | Unifreeze BS 20L | COOL90 at JPY 203 per 1 hour is the lowest number of the 5. |
| No. 2 | Unifreeze LT 20L | 0.4kg lighter than No. 1 and JPY 3,400 cheaper, but JPY 10 higher per 1 hour. A narrow gap. |
| No. 3 | Fixell BS 22L | A newer generation that is 2L bigger, but at JPY 319 per 1 hour it does not reach the 2 above. |
| No. 4 | Cool Line α III GU2000 | The list price is the No. 2 cheapest, but with KEEP51 it comes to JPY 345 per 1 hour. |
| No. 5 | PV-REX GU2200 | KEEP70 is the higher of Daiwa's two, but 5.1kg is the heaviest of those lined up. |
| Out of the ranking | Freega Basis 200 | 3.0kg is the lightest of those lined up, but because it is I-CE, its cooling cannot be compared on the same scale. |
No. 1 Shimano Unifreeze BS 20L | COOL90, JPY 203 per 1 hour
The deciding point is getting COOL90 for JPY 18,300. The inside length is 45cm, a length that makes it easy to bring a fish home without bending it. A four-corner lock pulls the gasket in, and Shimano claims it will not leak even when half filled with water and tilted 60°. That part is nice.
The point to watch is height: the inside is 21.2cm. It is the one for people who want to lay a long fish flat inside.
No. 2 Shimano Unifreeze LT 20L | JPY 14,900 at 3.8kg
The same box as No. 1, with the insulation changed to expanded polystyrene to make it 0.4kg lighter. The cheapest of those lined up.
This part is so-so. COOL is 70, 20 below No. 1. It suits day trips where you want to cut weight and price first.
Image: Rakuten Ichiba
Shimano Unifreeze LT 20L ND-720Y
Lowest price on Rakuten: JPY 10,780 (as of Oct 14). Some stores go up to JPY 14,778. Prices change daily.
RecommendedSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanNo. 3 Shimano Fixell BS 22L | lid opens from both sides
The new Fixell released in July 2026. The 22L opens from both sides, and the lid also comes off. Inside is resin with an antibacterial agent. It is built with even the washing in mind, and that is plainly good.
The point to watch is the price. It costs JPY 7,200 more than No. 1 and COOL drops by 10. It is the pick for people who can pay for how easy the lid is to use (pick 1).
Image: Rakuten Ichiba
Shimano Fixell BS 22L NF-622Z
Lowest price on Rakuten: JPY 17,815 (as of Oct 14). Some stores go up to JPY 24,517. Prices change daily.
RecommendedSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanNo. 4 Daiwa Cool Line α III GU2000 | 4.0kg of urethane
Light. Urethane insulation at 4.0kg. It is the lightest of the 4 urethane models, at a list price of JPY 17,600.
The so-so part is the KEEP51 number. The same series' SU2000 (vacuum panel in the bottom) is KEEP66 at JPY 25,400. It suits people who want to stay with Daiwa and people looking for a light urethane cooler.
Image: Rakuten Ichiba
Daiwa Cool Line α III GU2000
Lowest price on Rakuten: JPY 12,979 (as of Oct 14). Some stores go up to JPY 15,488. Prices change daily.
RecommendedSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanNo. 5 Daiwa PV-REX GU2200 | a 22L with KEEP70
KEEP70 is the higher of Daiwa's two. The inside is 24 × 35.5 × 23.5cm, and the height is more than 2cm over No. 1's in this group.
The point to watch is the 5.1kg weight. It is the heaviest of those lined up, and with ice and fish the gap widens further. For people who use it close to the car.
Image: Rakuten Ichiba
Daiwa PV-REX GU2200
Lowest price on Rakuten: JPY 18,308 (as of Oct 14). Some stores go up to JPY 22,352. Prices change daily.
RecommendedSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanOut of the ranking: Shimano Freega Basis 200 | 3.0kg with a vacuum panel in the bottom
3.0kg. Light. It adds a vacuum panel to one bottom face of an expanded polystyrene box. For people who carry it a long way on foot, this lightness counts.
But its cooling number is I-CE 35h, which cannot be lined up with COOL or KEEP. That is why I left it out of the ranking.
If you shoulder a cooler out to the boat or the breakwater, it is also time to review what you wear at the waist. I have also put up the life jacket ranking comparing Sakura Mark Type A.
If you carry it by train or on foot
The 25L with carry wheels released in September 2026, the Sea Cool Carry III review, is also a candidate. Every grade has non-slip feet, it is a size that fits through a ticket gate, and the GU2500 is KEEP65.
Overnight is a different story. For fishing of one night or more where you cannot add ice, you can also choose one step up in capacity or insulation.
For a folding cooler, I have also written the Soft Cool 2 review.
FAQ
Can KEEP and I-CE be compared?
No. KEEP and COOL have the same official method description, but Shimano itself separates I-CE as a different notation.
How much does adding a vacuum panel to the bottom change?
On the Unifreeze 20L, against the BS's COOL90, the CF with a vacuum panel on 1 bottom face is COOL95. The list price gap is JPY 7,600.
Does a long fish fit in a 20L?
It depends on the length. The Unifreeze 20L is 45cm, the Fixell 22L 40cm and the Cool Line α III 2000 39cm.
Gear in this article
Ads and images: Rakuten IchibaSources
- Shimano official: Unifreeze 20/30L
- Shimano official: Fixell
- Shimano official: notice of a delayed release for part of the Fixell lineup
- Shimano official: Freega 20/26L
- Shimano official: new product special site, 2026 AUTUMN & WINTER
- Daiwa official: Cool Line α III
- Daiwa official: PV-REX
- Daiwa official: Sea Cool Carry II (explanation of KEEP)
