The 11mm inboard clam shell batten end is specifically designed for use with mainsails featuring a bolt rope. It can be mounted at a 45 to 90-degree angle from the mast, making it ideal for square top or pin head mainsails. The central plastic component is typically inserted into the batten pocket, while the two side plates secure the unit from the exterior. When installed tightly against the bolt rope, there is no need for a bumper as the sail can easily glide along the mast track. Crafted from UV-stable plastic with stainless steel fasteners, this batten end is built to last.