If you are worried about leaving your helmet on your bike, go for NEWGTBE Number lock. This would make sure that you never face any such problems when you leave the helmet with your ride again.The cable is made from metal making it very hard to cut through, the length of the cable is moderate as it will easily accompany the thickness of the helmet and various parts of the bike. It also features a 4 digit lock, which will enable you to keep a safety code that will unlock the chain when you need to. This lock code comes predetermined and so you cannot change it. The helmet also features a stylish design in black that would go well with any bike.