Constructed from 7075 aluminum with precise machining. Hard green anodized for durability with laser engraved torque recommendations. Nice deep finger splines allow for easy usage while hands are greasy. Compatible with 3/8" square drive ratchet or torque wrench. AT-0001 is compatible with all outboard bearing cups that the dual sided model does not fit (AT0002) including Campagnolo, SRAM, FSA and older Shimano models. AT0003 is compatible with Shimano DA-9000, XTR-BB93, Ultegra 6800, 105 5800. AT1090 is compatible with Chris King bottom bracket models. AT1093 is compatible with Praxis bottom brackets. Made in the USA; Bend, Oregon