Schaefer 74-24 Control Block/Double Sheaves/Cam - 1-1/8" Track - Starboard Cam Cleats_Bullseye The 438 adapter plate is

The 438 adapter plate is perfect for mounting on masts and booms

The precision-engineered

They can be used for tie-downs or other rigging applications

They roll freely on low-beam to permit adjustment under load

Schaefer 74-24 Control Block/Double Sheaves/Cam - 1-1/8" Track - Starboard Cam Cleats_Bullseye The 438 adapter plate isThis double sheave control block with cam cleat fits Schaefer 1 1 8" traveler track. It provides clean, simple adjustment and allows up to 3: 1 purchase, which greatly reduces effort required to pull the traveler car to windward. The new fast entry cam may be moved to 3 locations for the correct lead.