The toughest, rock solid, and high-security Strongman. Combining hardened steel housing with investment cast stainless steel cover and a 13mm hardened steel shackle, over-molded with UV resistant silicone. Basically, means it won't mark or scratch your bike but could kill a beast. The Knog Strongman has a torsional strength that can withstand forces of up to 2kNm of combined twist mass force and is frost, dust and corrosion resistant. The Strongman U-lock is both Stitching ART (3 star) and Sold Secure Gold accredited*, which are the highest security accreditations in the UK and Netherlands for Bicycle Security Systems.