Concealed electric hinges conduct current, regardless of door position, to electric locks, exit devices, or hold open devices where tamper-proof hinge is required. Also to transmit signals from code readers on doors to remote computers for access control. No electrical parts are exposed when hinge is installed. Hinges should be installed in the center hinge location of the door. The electric hinges line consists of standard commercial grade door hinges. This makes them an ideal fit for wood and metal doors, medium to heavy weight doors and medium to high frequency usage applications. Steel hinges are a good fit for interior applications whereas stainless steel hinges are ideal for exterior or corrosive environments.