1-button aluminium telephone extension Telephone extension with speakerphone function, flush-mounted or surface-mounted 1300 entrance panel version with 1 button for telephone calls (with programmable telephone number) and two with N.O. contacts for controlling 2 independent external services (e.g. lock release with relay 170/001 and transformer M832), can be activated automatically during conversation from a telephone call and programmed from a remote telephone, electropolished anodized aluminium
