These are a set of 2 specially designed clamps that attach either the Beastie Base or the Beastie Bar Stands to the rails. The clamps slide freely up and down the rails to adjust the position of the massage tool, and are locked in place with their thumbscrews. You then lean against the massage tool to apply massage pressure to your body. The same clamps are used for holding either the Beastie Base or the Beastie Bar Stands, and the Beastie Bar Stands can be clamped in either a vertical or horizontal position, allowing you to employ different massage techniques. The clamps hold the massage tool tightly, but also allow you to quickly reposition the tool as needed. Repositioning requires just a 1/4 turn of each easy-to-operate thumbscrew. It\'s also very easy to add or remove clamps and massage tools to your Beastie Wall System, even after it\'s mounted to the wall. With the thumbscrews loosened an extra 1/2 turn, the entire assembly can be slid off the top or bottom end of the rail.