This is a mechanical bottom insulator for the 510 threaded Hercules Oil Cartridge. This bottom insulator fits 510 threaded Hercules only and will not fit any previous (SR series or earlier) Hercules. It's subject to wear and may require replacement if the Hercules has been repeatedly overtightened.
This insulator has two o-ring grooves for compatibility with the Nibbler XL Bubbler.
It features a user adjustable pin that requires proper and occasional adjustment for to ensure connectivity: Hold one screw and turn the other 90° counter-clockwise, check and repeat if necessary until contact is made.
Please contact our Support team if you have any questions about the suitability of this piece for your Hercules before purchasing.