Very secure.
The BikeBox has achieved a number of endorsements and awards in the UK from the insurance, security and policing sectors (outlined elsewhere on this site).
The Standard model features 4 external stainless steel locking points, an internal anchor, locking cable and padlock and 2 further padlocks for external use.
The Slimline model has 4 stainless external fixing points and is supplied with 2 padlock.