This tool conects two ratchets together. This gives leverage to the second ratchet in any direction especially when working in tight places. We have 4 different tools for this 1/4 Ratchet to 1/4  Ratchet, 3/8 Ratchet to 3/8 Ratchet, 1/2 Ratchet to 1/2 Ratchet, 3/4 Ratchet to 3/4 Ratchet.