The Lezyne Cnc Alloy BB Tool 4116 (41MM) Hollowtech II is a durable workshop tool. The tool works with a socket wrench or 32 mm open-end wrench. The serrated outline makes the Lezyne Cnc Alloy BB Tool 4116 (41MM) Hollowtech II a versatile bottom bracket tool. The tool is manufactured from premium aluminum with an anodized black finish.