Heavy duty SPDT non-latching Footswitch. as used in guitar and music effects pedals. Non latching.... which means that although there is a very positive "click" sound and more inportantly a "click" feel, this switch only changes poles while being depressed. as it's a SPDT (Single Pole Double Throw) by selecting which pair of the three contacts you use, it is iether "ON" or "OFF" when pressed or "ON" or "OFF" when not depressed. If that really depresses you then please look at the diagram in the second picture which clearly shows this action. Dims: Button : 10mm dia. with 5mm. throw. Total height of switch (top of button to base): 42mm , switch base (black bit) 17 x 17mm which includes side fitted solder tags) Status: NOS (New Old Stock) a rare find, built to a high quality, NOT a Chinese import Comes with 2 x locknuts, 1 x lock washer, 1 x plastic washer RoHS compliant: no