Oxballs Ergo X-Large Silicone Butt Plug - Black The Oxballs ERGO PLUG is a smooth silicone butt plug with a flared base and ergonomic kidney-shaped design. The soft silicone flanges at the base keep the ERGO PLUG securely snug between your cheeks. Each unique ERGO PLUG is hand poured at the Oxballs factory so no two plugs are alike. Lube: Water-based (recommended) Cleaning: detergent and hot water, diluted bleach/water solution, dishwasher. Measurements: Length: 6" / 15.24 cm Usable Length: 5.75" / 14.605 cm Largest Usable Circumference: 8.5" / 21.59 cm Smallest Usable Circumference: 4.75" / 12.065 cm Weight: 1lb 4 oz