What does it mean if my current lead reads "OL" on a multimeter

The Johnson Controls VG1241BN Ball Valve is a 3/4-inch NPT two-way control valve engineered for precision regulation in closed-loop HVAC systems

It features a high-grade solenoid valve piston assembly

this is a proprietary Berko heater accessory

Trane SWT3968 Rollout Switch 323269-701 What does it mean ifThe Trane SWT3968 Rollout Switch is a critical safety component engineered for gas fired furnaces and HVAC systems. As a genuine OEM replacement part, this manual reset flame rollout switch is calibrated to open the electrical circuit when internal temperatures at the burner box exceed the fixed threshold of 190F (L190F). Designed with an enclosed stainless steel disc and high grade unplated brass terminals, this SPST (Single Pole Single Throw)