Swell is a sheath that strokes the guy while he pumps.. the inside shaft is loaded with nubs and more "headroom". Swell adds girth and length to you. MATERIAL: plus+siliconeTPR/silicone blend LUBE: Safewithwaterandsiliconelubes,oil-baselubesnot DIMENSIONS: L:8.25”W:2-2.5” Main Hole Circumference:4.5” Shaft Hole Circumference:3.5” Inner Shaft Depth:5.5” Ball Hole Circumference:3.5” Shaft Circumference:5.75”-7”