21.18.101 The power switch required by 21.17 shall be a momentary power switch without a lock-on device, which can be switched on and off by the user without the need to release any of the handle(s) or grasping surface(s) required by 19.101.When the lock-off function as specified in 21.18.102 is in the unlocked state, the chain sawshall operate within 1 s after actuation of the power switch.The chain saw shall only operate when the chain brake, if any, is deactivated.Compliance is checked by inspection and by manual test.