What is difference in behavior of MGU3.108T.xx and MGU3.107T.xx?

MGU3.108T.xx, switch
MGU3.107T.xx, push-button

Switch - when pressed, the rocker remains pressed even the finger doesn't hold it anymore. The load is switched off by limit switch or by short press of the rocker for opposit direction.

Push-button - only when it is pressed and held the circuit is in ON state. The load is switched off by finger release or by limit switch. The rocker gets back to default position.

Released for:Schneider Electric USA