The Allen 20mm Dynamic Block Linked is designed for use in dinghies, windsurfing, kitesurfing, and other applications that require smaller diameter lines. Its lightweight and sturdy construction, as well as its low friction and fast-rolling capabilities, make it an ideal choice for these activities. In particular, the patented bearing system of stainless steel ball bearings running on a stainless steel rail sets it apart from other block systems and provides superior load-carrying ability and longevity. Additionally, the 20 and 30mm blocks have a large central rivet for reduced weight and rope-friendly attachment, making them excellent options for use in cascade systems.