Options & Accessories For Valve Automation Requirements Factory Sealed Leads Eliminate the possibility of conduit contamination and the need for seal fittings with Proximity's factory sealed (potted) leads. This seal has been UL tested to 6000 PSI (422 kg/cm2) and listed for Class I, Groups A, B, C, D; Div. 1 & 2 atmospheres. Groups may vary depending on the switch model. Standard leads are 18 AWG and 36" (91.44cm) long.