With 412 Double Cam Cleat
Use Cam Swivel Bases when leads must rotate to face the trimmer. Ball bearing swivel bases feature dual rows of Delrin® ball bearings that swivel freely even under high loads. Bases include stand-up springs and a U-adaptor to accept a variety of appropriate blocks. Delrin® is a registered trademark of E. I. du Pont de Nemours and Company or its affiliates.
The 402 is fitted with a double cam for use in two-speed mainsheet systems.