






🏄♀️ Ride the wave of innovation with fins that flex, flow, and fly!
The UPSURF K2.1 5-fin set features lightweight fiberglass honeycomb construction designed for single tab surfboards of all types. Engineered with new linear flex technology, these fins deliver smooth 3D twist and roll action for enhanced control and responsiveness. Available in multiple vibrant colors, they combine professional-grade performance with affordability, making them a top choice for intermediate to advanced surfers seeking reliable, versatile fins.




| ASIN | B0748BZRXG |
| Age Range (Description) | Adult |
| Best Sellers Rank | #292,887 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #117 in Surfing Fins |
| Brand Name | UP SURF |
| Customer Reviews | 3.6 3.6 out of 5 stars (41) |
| Date First Available | July 25, 2017 |
| Included Components | 5 set fin |
| Item Package Dimensions L x W x H | 7.24 x 6.54 x 1.89 inches |
| Manufacturer | UPSURF |
| Model Name | Surfboard fin |
| Package Weight | 0.25 Kilograms |
| Part Number | CA-K2.1 |
| Skill Level | Intermediate, Advanced |
| Suggested Users | unisex-adult |
| UPC | 606860847399 |
| Warranty Description | NO |
T**R
Great!
Better than plastic, and great. I’m not sure about the scientific specs between this and let’s say FCS or FUTURES, but man it’s 1/3 the price!!! Can’t go wrong. Good quality, plenty of sizes to choose from.
C**Y
Haven't had them in the water yet but can say ...
Haven't had them in the water yet but can say they appear to be a decent set of fins for the price. I matched them to the K2.1 FCS I have and the templates match. There appears to be carbon in the shaded areas and is definitely not paint.
T**F
Below average quality
Poorly made product. I also wanted fins for a quad and didn’t receive that
C**N
Vertical surfing
These fins fit nice and snug but once you get them in and out one time the get put in pretty easily. Very solid feeling had no problems with construction. Standard Honeycomb feel for flex. allows for very pivotal surfing a little extra loose off the top. if you need more hold just put the quad on. still very loose with the quad though. Would recommend if your looking for a 5 fin cheaper set that isn't made by futures
C**E
Save money- awesome quality
The fins are made of good quality materials and work exactly the same as the real Kelly Slater 2.1 fins I've used for years! I highly recommend these fins.
G**D
Decent tri-quad set at unbelievable price.
They seem well made. The foil is nice, nicely rounded leading edge and a good taper to the trailing edge. These are close to a pivot fin. Check the dimensions because I thought I ordered a large set but they’re more like a medium. Now the ad only has the dimensions and no size, so just check the numbers and you’ll be good. Flex is nice, not too soft or stiff. These are foiled much, much nicer than other cheap imported HC fins I’ve seen. 5-fin Quad set for $42. You can’t even get a set of HC quad trailers for that.
A**R
Great price!
I ended up getting a really good price on these. The fins do the job. You can't really ask for more than that.
P**.
Broke within 6 months of use
Been using these for a bit but today one fin just straight up broke off.
Trustpilot
2 days ago
2 weeks ago