The Squid Grip insert is a revolutionary rail cover made specifically for the TRX Extreme, Alpha, and Delta Series Battle Rails with the round vent holes. Made from an advanced rubber that is extremely heat resistant and durable. The Squid Grips insert directly into the cooling holes and are 6 holes long, but can be cut to any length. Made in the USA. Notes:Compatible with Alpha Rails, Delta Rails, TRX Extreme Battle Rails, HK Battle Rails and T-22 Sport Chassis