Abstract: A keyboard assembly is shown utilizing a keypad formed from a sheet of soft rubber having a plurality of dome shaped portions. A conductive layer is disposed on the bottom surface of each dome shaped portion and is aligned with spaced interdigited conductive runs on a substrate at a switching station and is adapted to move into and out of bridging electrical contact with the spaced interdigitated runs. The keypad is compressed around the switching stations to form an environmental seal by ribs formed on an escutcheon and held there by posts projecting from the escutcheon through the keypad and substrate and deformed against the substrate. The substrate may be a flexible membrane supported by a rigid plate or it may be a circuit board type member. The dome shaped portions are integrally vented by a channel formed in the keypad extending between the dome shaped portions.