The Ajax DIN holder is ideal for securing a Relay or WallSwitch and is made of durable black polycarbonate weighing only 9 grams. Measuring 52 × 41 × 18mm, the holder with the relay installed is the same width as a single-phase circuit breaker.The holder can be installed in places with humidity up to 75%. Included with the holder is a set of stickers that will help identify which circuit or device the relay controls and brief instructions