For removing stiff backnuts Rapid tap installation for 1/2-inch BSP & 3/4-inch BSP Taps Tool stays in position on the tap tail Complete with 3/8-inch cordless drill adaptor, 1/2-inch square drive Extension tube The Monument 173 has been especially designed for removing stiff backnuts from awkward placed taps & to make tap installation a more rapid process, this tool is for 1/2-inch. BSP & 3/4-inch. BSP taps. The Monument 170 tool stays in position on the tap tail so can be used with one hand & uses mechanical advantage of the thread of the tap tail to remove stiff nuts. Ideal for 1/2-inch & 3/4-inch BSP 25 mm 27 mm nuts 29 mm ribbed 32 mm nuts. The MON173 is complete with 3/8-inch cordless drill adaptor, 1/2-inch square drive, extension tube & full user instructions. For removing stiff backnuts & rapid tap installation for 1/2-in CH. BSP & 3/4-inch. BSP Taps. Tool stays in position on the tap tail. Uses mechanical advantage of the thread of the tap tail to remove stiff nuts. Monument Stiffnuts Professional Boxed Kit. 1/2-inch. & 3/4-inch. BSP 25 mm 27 mm nuts 29 mm ribbed 32 mm nuts. Complete with 3/8-inch. Cordless drill adaptor, 1/2-inch. Square Drive; Extension tube & full instructions.