The Tessi 'Snap Safe' cylinder has a built-in weak spot (snap line) which is designed to break if the cylinder is forced. However, the lock will not fall apart as a result, and the door will remain locked. The owner of the house can still gain access with their key when they return. Each cylinder has been specially designed to be anti-pick, anti-bump, anti-drill, and anti-snap. Available in a 35/35 size.