Blackstone Bike lock is an ultra-strong used independently approved 14mm shackle lock with hardened steel construction. As well as being an extremely secure lock, it has a built-in alarm triggered by movement sensors. This Heavy Duty 10mm six-sided square-linked chain links made of 2t HARDENED MANGANESE STEEL for ultimate strength, making it ideal for outdoor use.

• Blackstone Bike lock is an ultra-strong used independently approved 14mm shackle lock with hardened steel construction.
• The package includes: 1 Alarm U Lock, 1 CR2 lithium battery, 3 keys, 1 chain, 1 bag.
• The bike U-lock comes with 3 keys. One of them you can take and use in daily life and the others you can leave at home in case the trouble. Also, It comes with a key replacement Code card from which we can help you to equip a new key when you lose them all.
  
• This heavy-duty 10mm six-sided square-linked chain link is made of 2t HARDENED MANGANESE STEEL for ultimate strength, making it ideal for outdoor use; it also features a nylon sleeve against scratches to bicycle and motorcycle surfaces.
• The World's Only 130db Loud Alarm System will automatically activate upon sensing any vibration or shock and is loud enough to scare off thieves. Loud Alarm System provides Maximum Protection for e-bikes Electric Bikes Scooters & Motorcycles.