The bundle includes: MacBook Pro with Retina Display - 13" or 15" Security cover/skin (adds 0.35lbs), MacBook Pro with Retina Display - 6 Feet low profile steel 4 Dial security Combo lock. Maclocks security cover (patent pending) is a simple, yet clever solution which incorporates a security slot into the actual MacBook Pro cover (Only adds 0.35lbs when using the lower skin and 0.7lbs when using it as a shell) a similar solution is offered for the MacBook Air.This smart skin mechanism, slightly elevates the MBP above the surface thus enhancing current venting system. The polymer security cover is engineered to support the MBP cooling process. That way you can lock the security cable to the MacBook Pro case, and loop the cable's other end around a fixed object such as a table leg (or an anchor point which is available at Maclcoks.com). Once the case and cable are locked together, it's hard to detach the case without damaging the MacBook Pro.