Our INSIDER™ Box Ratchet 3/8" Anvil Adapter is designed to uniquely fit into our M12 FUEL™ INSIDER™ Box Ratchet allowing use of existing 3/8" drive sockets and to protect the investment you've already made while delivering on performance and productivity. INSIDER™ Box Ratchet Adapters are available in ¼”, 3/8”, ½” & ¼” Hex, providing you with Ultimate Versatility.