Complex sentence: Higher security lever locks (such as the 5 lever) usually have notches cut into the levers-which catch the locking bolt and prevent it from moving if picking is attempted (similar to the security pins in a pin tumbler lock).
Split into simpler sentences: Higher security lever locks (such as the 5 lever) usually have notches cut into the levers. These catch the locking bolt and prevent it from moving if picking is attempted (similar to the security pins in a pin tumbler lock).