K4 Fins - In-house fin design for riders who tune their setup

K4 Fins is a UK-based brand focused mainly on windsurf fins, with a smaller range for surf and SUP. The brand is made for riders who care about how a fin changes grip, release, drive and control on the water. Its approach is built around in-house production, plastic composite materials and a clear focus on flex, reflex and precise fin feel.

What makes K4 Fins stand out?

• K4 makes its fins in-house in the UK using plastic composite construction designed to add flex, reflex and performance
• Dynamic Flex material is made for a looser, grippier wave feel, especially through turns and at high angles of attack
• Super Stiff material gives an alternative feel for larger fins, heavier riders and stronger loads, with more straight-line performance and fast reflex
• The range is strongly focused on windsurf wave fins, freestyle, freeride, speed and weed setups rather than a very broad watersports catalogue
• K4 CNCs and moulds its fins using precision moulding techniques, giving the brand direct control over design and quality
• Some fin ranges have been developed with the Official Test Centre in Weymouth, adding rider feedback and testing to the design process

Who is K4 Fins for?

K4 is for windsurfers who like to fine-tune their board rather than simply ride the standard setup. Intermediate, advanced and expert riders will get the most from the range, especially when adjusting rake, looseness, grip and drive in multi-fin boards.

A freestyle windsurf fin such as the ZBD suits riders looking for release and control in freestyle moves. Riders using a windsurf weed fin will find options aimed at cleaner tracking and reduced weed catch in difficult spots. In surf and SUP, K4 is more specialised, with FCS1, Futures and SUP race fin options for riders who need control, tracking or weed clearance.

K4 Fins products at EASY-surfshop

At EASY-surfshop you will find selected K4 windsurf fins for wave, freestyle, freeride and weed setups, including recognisable models such as Scorcher Rear, Dugong Rear and ZBD Freestyle Fin. The range also includes practical spare parts and accessories, such as K4 Fins Blankers for unused fin boxes, helping reduce drag and turbulence.

When choosing a fin, start with your board’s windsurf fin box, then match the model to your discipline, conditions and preferred feel on the water. K4 supports common systems such as Slot Box, Power Box and Tuttle Box, including spacer options for Tuttle and Deep Tuttle setups. A slot box windsurf fin will be the right direction for many modern wave boards using compact multi-fin layouts.

Browse the K4 Fins range at EASY-surfshop and find the setup that matches your riding style.