Harken's Standard Low Profile Cam Base ﾖ Swivel is ideal for mounting at deck level and with smaller blocks such as Harken's line of 57mm, Big Bullet, Dinghy, and little ratchets. The cam accepts a minimum line diameter of 1/8 in (3.2mm) and a maximum line diameter of ﾽﾔ (12.7mm). This low profile configuration's swivel features dual rows of Delrin ball bearings that swivel freely even under high loads. The swivel base with cam is often a component in a 4:1 traveler car mainsail adjuster with a curved traveler track and a 16:1 double-ended fine tune system. This low profile swivel base is engineered to be used with Harken's (2 1/4 in 57mm, Big Bullet, Dinghy, and little ratchet blocks.