The best-selling Aneros Helix is aggressively shaped and angled, providing immediate pressure and tension on the prostate and surrounding area. It requires less patience and practice to realize benefits. The Helix was designed based on feedback from our customers and several additional design patents. It has a sharply angled stem and large bulbous head which provide a more aggressive prostate massage. The redesigned P-Tab provides a more focused external prostate stimulation when massaging the perineum. In terms of dimensions, the Helix is larger at the tip (1 1/16 versus 0.9 on the MGX) and is more angled to provide a more vigorous massage. However, the mid-ridge is slightly smaller (1/16 smaller) on the Helix. The Aneros Helix Male Prostate Stimulator features: Larger bulbous head with flat, wide head for more contact with prostate, Strong angled stem for greater pivoting ability, Dime perineum tab. The Helix is great for adventurous beginners and advanced users.