The low-profile Flip Flop blocks are lightweight and can be used for various leads on your boat including halyard leads, mainsheet leads and spinnaker sheet leads. The high load Flip Flop blocks pivot around the line axis to keep the line close to the deck. Hinged construction allows variable leads. Lockoff provides a temporary stop to free up winches. 3" x 2-7/8" x 6". Maximum working load, 5000 lb.