KDT GearWrench 81016T -1/4" Locking Flex Head Ratchet - 90 Tooth. Manufacturer's Part Number: KD GearWrench 81016T, KDT-81016T, or KDT81016T. GEARWRENCH ratchets help you GET IT DONE. Teardrop, low-profile head and flush-mounted on/off switch allow better access in tight spaces.