XR Brands Tom Of Finland Barrel Nipple Clamps. This heavy duty set of barrel style nipple clamps are adjustable, with removable 4 ounce weights. The body of the clamp twists, to tighten or lessen the pressure. Made of heavy duty metal and tipped with rubber for grip and comfort. Measurements: 4.57 inches in total length, opens up to 0.5 inch in width. Material: Coated brass, thermoplastic rubber TPR. Color Black. Note: free collector print included!