It is probably cheaper to just replace the unit with a key entry Box so you can lock it.
Nestor's
www.NestorsLandscape.com
www.UniqueLighting.net
vincent nestor
Vincent Nestor
Nestor's Sprinklers & Lighting
Alpharetta,Ga.30022
vpn1@bellsouth.net
www.NestorsLandScape.com
www.GeorgiaLighting.net