Pactrade Marine Boat Bilge Alarm Pump Switch Aluminum Plate Manual Automatic This is a stamped anodized aluminum bilge pump switch and this product features both automatic and manual settings Two means of alarm (visual and sound) are activated when water level in your bilge is beyond your bilge pump float switch level Operation manual: See picture attached to this listing with drawings and instructions Measurements: 2.5" by 4.5" Item: P10298