The EXTECH SL250W Sound Meter with Connectivity to ExView® App features an easy, flexible operation and provides up to 90 m wireless connectivity. The EXTECH SL250W is part of the EXTECH "250W Series" family of connected meters, the 250W series can be used together in any combination (up to 8 meters). The EXTECH ExView application allows the SL250W readings to be displayed on most mobile devices.