Make sure that manual shrink sealer machines you use for industrial purposes are properly maintained by choosing from the selection of manual shrink sealer replacement parts and accessories available at Technopack Corporation. Parts for JORESTECH® models FR-400, SHR-300, SHR-450 and SHR-600 include the circuit plate PCB for the SHR Series, heating elements and PTFE Kits, potentiometers, cleaning switches, ON/OFF switches, selector knobs, transformers, rollers, micro switches, bottom silicone rubber and terminal assemblies. The potentiometer is a variable resistor that functions in conjunction with a knob. The user turns the knob, and the rotational motion is translated into a change in resistance in the electrical circuit. Most of the products that are found on the Technopack Corporation's website can be purchased online with immediate availability in its warehouses.