This document outlines the testing carried out on a QuaeroSys piezostimulator for use with an electro-magnetoencephalography setup, at the Medical Research Council’s Cognition and Brain Sciences Unit in mid-2015. The document includes a guide for setting up and running the stimulator, and the results of tests that were run on it, including tests of clock speeds; latencies; EMEG compatibility; internal clock accuracy and memory buffer limits.MRC Cognition and Brain Sciences Unit