This will prevent damage to the unit due to lightning and power line surges. Bosch Security Systems | 29 March 2004 LTC 8557 Series | Instruction Manual | Safety Precautions EN |3 Safety Precautions For Indoor Product 1. Water and Moisture - Do not use this unit near water - for example, in a wet basement, in an unprotected outdoor installation, or in any area classified as a wet location. 2. Object and Liquid Entry - Never push objects of any kind into this unit through openings, as they may to