The high-strength composite T2â„¢ 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 SpectraÂ® line is included. SpectraÂ® is a registered trademark of Honeywell International, Inc.