Swell is a sheath that strokes the guy while he pumps the inside shaft is loaded with nubs and more headroom. Swell Cock Sheath adds girth and length to you. Materials plus+silicone Thermoplastic Rubber TPR, silicone blend. Lube safe with water and silicone lubes. Do not use oil based lubes. Dimensions total length 8.25 inches by 2 inches to 2.5 inches width. Main hole circumference 4.5 inches, shaft hole circumference 3.5 inches. Inner shaft depth 5.5 inches.  Ball hole circumference 3.5 inches. Shaft circumference varies from 5.75 inches to 7 inches.