SCR25A Used with Bogen SBA225 and SBA325 Room Selector Panels in Multi-Graphic systems Function: Provides silicon controlled rectifiers allowing use of momentary switches for call origination SCR Quantity: 25 Termination: Centerline pins (Bogen 25-Series Connector Kit recommended) Dimensions: 16-3/4" W x 3/4" H x 3-1/2" D Weight: 8 oz.