The Lascells Strobe Frequency Counter provides a compact, economic, reliable and simple way of detecting the frequency of a strobe light source. Although designed to work with the Lascells ripple tank, allowing a quick measurement of strobe frequency, the unit can also work other strobe light sources. To use, simply turn the device on, place it onto a closed mini ripple tank or facing a strobe light source and the frequency of the strobe will be displayed. The device is accurate from 1 Hz to 1 kHz (which exceeds the strobe range of a Lascells ripple tank). Comes with rubber feet to protect ripple tank top surface and is supplied with full instructions. Dimensions: 76 x 52 x 30 mm (l x w x h). Requires a 9V PP3 type battery (not included).