20mm Single With Swivel Hook Dynamic Block.

The A2020 is a low friction, fast rolling, small pulley. It’s lightweight and strong, making it ideal for dinghies, windsurfing, kitesurfing and anything else that runs smaller diameter lines. 

Allen's Dynamic range is generally the best choice for applications that require constant sheave movement.

Swivel Hook – A built-in swivelling hook allows this block to be easily attached or removed as well as swivel to aline with pulling forces that may change direction. The swivel cannot be locked.