STOPXA E-stops are available in 29 mm and 40 mm mushroom operators in red, yellow or gray. 16 mm XA and 22 mm XW E-stop switches are now available with engraved EMO markings. When used in combination with switch guards, these E-stops comply with SEMI S2 standards, while only being 27.9 mm behind the panel (XA series) with up to four contacts.