Use Magna-Bit Allen head bits with the Seekonk 1/4" Drive Torque handles or Variable Torque Wrench for torquing rifle triggerguard screws. 1/4" socket has no magnetic insert. ZM23 Converter has magnetic insert and locking snap ring to securely hold all 1/4", hex drive bits. Mfg: Brownells SPECS: 1/4" Socket – steel, chrome plated 1" (2.5cm) long. ZM23 Converter – forged steel, heat treated, 2" (5cm) long.