Super-Bands™ polyurethane ring 3/4 inch ID black
Ships from US and is sold by Marco Specialties$1.60
Super-Bands™ polyurethane O-ring, standard 3/4 inch Inner
Diameter, black gloss.
Inner diameter is .75 inches (19mm) and the cross sectional
diameter is standard 3/16 inch (4.7mm).