The LOX-ES20-EL50 is an ANSI footprint electric strike that is site interchangeable forpower to lock (PTL) or power to release (PTR) through reversing the position of the 'barbell' inside the strikes housing; simply unscrew the spring screw cap, remove the 'barbell', reverse it and re-fix the spring screw cap. It is suitable for all types of wooden, steel, PVC, aluminium or stainless door frames. The LOX-ES20-EL50 is pre-drilled for extension lips, and comes with a 5 year warranty.