The Allen 20mm Double Dynamic Block with Fork boasts low friction and high speeds due to its lightweight design and strong construction. This makes it a preferred choice for smaller diameter lines in dinghies, windsurfing, and kitesurfing. The block's removable clevis pin and patented twin row bearing system offer easy attachment and superior load-carrying ability. Additionally, the large central rivet on the 20mm and 30mm blocks provides a lighter weight and rope-friendly attachment point for use in cascade systems.