Single Tii-On. The Tii range features the same bearing system as our Dynamic range but loses the Ultra-Strap to save weight. What differentiates our Tii blocks from other tie on designs is the large stainless-steel ring at the head of the block. This ring is designed to stop the block from capsizing once tied into a system as well as reducing the chance of the cheeks splitting apart. However, when splicing these blocks to an attachment that is wider than the block, a boom for example, it is still recommended that a cross splice is used to reduce the chance of splitting the cheeks.