If you're looking for spare parts or just something to put your cock into (flesh and blood or any manner of synthetic), you really can't go wrong with this little gem. It'll stay strong, and keep performing under a wide range of circumstances.
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A Symbiotic O-Ring
Looking for an affordable metal o-ring that won't damage your durable silicone toys? Then the Plated chrome ring by Doc Johnson is for you. If the rings were offered in a greater variety of colors, they would be 5 for 5.