Line 300 video handset. 2-wire technology, vandal-proof one-piece up to 8 calls in stainless steel finish. Includes flush-mounted box, frame, color audio video sound module and pre-wired button module. Provision for front mounting of a key switch. Backlit call buttons. Visual and audible indications for call in progress, system busy, lock status. Burglar-resistant screws. Allows activation of an electric lock connected directly between terminals S and S 18 V 4 A impulsive, 250 mA holding, 30 Ohm max.