Scotty #355 rodmaster II downrigger Boom rod holder has a 10" tube and is made of fiber reinforced engineering nylon that offers strength, resilience and reliability. Removable gimbal pin and front opening Slot Accomodates any rod and reel combination. This downrigger Boom rod holder fits 3/4" and 1" Scotty downrigger booms. This style bolts though the Boom.