1.Material: Made of stainless steel material, not easy to rust, not easy to corrode, not easy to fade, small size, easy to store, will not take up too much space, fine workmanship, long service life. 2.Size: As the picture show. 3.O-ring rubber ring design: There is a rubber spring on the fin screw, which can help bear the pressure, not easy to break, can be used for a long time, very practical and considerate design, these fin screws will protect your sup or paddle. These fin screws are great for any board with a center box fin set up. 4.Easy To Operate: This no tool thumb screws is easy to install, hand tighten the o-ring, no tools and no screwdriver needed to install, adjust or remove longboard fins or stand-up paddle fins, making you happier on the water, Suitable for beginners and those who like to surf. 5.Wide Application: Suitable for all standard surfboard fin boxes for longboard, single fin, paddleboard, inflatable , etc. M5*19mm-Phillips pan head stainless steel screw (for plastic single rudder) M4*19mm-Phillips pan head stainless steel screw (suitable for FRP single tail rudder) Weight: 8g Quantity: 1pcs Color: primary color Specifications: 23*19*5cm Material: Stainless steel