Protect your Elecraft PX3 knob, screen and buttons with this magnetic cover. Simply replace the screen cover screws with the included hex head cap screws, each one at a time. The new screws will position the cover to prevent any force on the knobs. The included magnets in the cover will secure the cover to the installed screws. Use with or without extended side rails. Now made in ASA for maximum protection against UV and heat that can cause warping.