This is a silicone propeller guard that I designed for propellers up to 50mm in diameter, including high rake props! Silicone guard will help protect your propeller in the event of a small drop and also helps protect car seats from your propeller while transporting. It is 10mm thick in each direction and simply attaches with the included rubber band. It is not guaranteed to fit all props and boats but was designed to fit the Sonicwake and similarly sized boats with strut mounted propellers, such as the Blackjack 42, Spartan, and M41.