Harken Block 57mm T2 Soft-Attach Loop Block for catamarans, this tie-on block eliminates the need for shackles, posts, swivels, etc. It is ultra-lightweight and sized like a bullet-block. 

The T2 Loop Block's on/off loop system slides through the block head and over the anchor post for a secure connection.

Specifications:

• 2-1/4" sheave diameter
• 792 lb. SWL
• 2380 lb. breaking strength
• 7/16" maximum line diameter

Harken Part # 2151

The high-strength composite T2™ is the first block with no metal shackles or rivets. It is used for traveler controls, mainsheets and vangs, cascades, bridles, and other systems where small, lightweight blocks are called for. The T2 can be tied, spliced, or lashed to almost anything. A length of Spectra® line is included.