A BDSM Fetish nipple clamp chain made of metal. It's awesome.
discountdungeon

Basic Nipple Clamps w/Chain

Regular price $5.99 Sale price $14.99 Unit price per
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Please allow 28 days for delivery. Some items may take longer.

You can clamp these to nipples, and then pull on the chain. Good times mostly guaranteed, unless you clip these to a bear's nipples.