Send wannabe thieves back to the darkness scratching their heads with the Kryptonite Kryptolok Combo U-Lock. With a high-grade hardened carbon alloy steel construction, this lock's shackle resists hand tools with force, while the four-digit combination simplifies things by eliminating the possibility of losing keys. Its centrally-located mechanism helps defend against leverage attacks, while the bumpers reduce rattling noise when you're transporting the KryptoLok from spot to spot.