Specifications: 1 1/6" diameter at the tip, 15/16" diameter at mid-range, 1 3/4" from the main body to pressure point. The Helix is larger at the tip (1 1/16" versus 0.9" on the MGX). This item has an insertion length of 4 inches. The Helix also has a stockier base, larger tip and is more angled for extra vigorous stimulation. Use: Place the head into the anus (similar to a butt plug). Make sure that the curled arm (handle) is between the buttocks and the upturned arm touches the perineum. The item itself should be tilted forward.