Today there is a need to know just how loud your surroundings really are. The checkmate cm140 is a high performing tool to measure spl in decibels (db). Convenient mini size, max/min function with 140db max, level range display, ac signal output and resolution .1db. The cm140 meets the same iec 651 type 2 and ansi s1.4 type 2 standards of spl meters that cost five times as much or more. Windscreen and battery included.