The Hobie H-Rail Ram Ball attachment allows you to attach Ram Ball mounted accessories to the Hobie H-Rail. The Ram ball clamps to the 12-sided H-Rail without any drilling or tools needed. When the clamp is secured, the Ram ball does not twist or slide along the rail. Loosening the clamp allows you to remove the accessory or slide it along the length of the rail. Fits the H-Rail on all 2015 Pro Angler 12, 14, and 17 kayaks.