You'll notice on the Helix's page in the Aneros shop, the insertable length is labeled with one end at the head of the massager and one end waaaay down where the body curls in and the base begins.
I'm fairly certain I've only been inserting it to the second "dip" or slimmed portion of the massager (counting from the top in that picture.) I've had some really great sessions this way so I'm pretty sure I'm not missing anything, but just to be 100% certain...
Do others insert it all the way to the end of the insertable length labeled in the picture?
I don't think it's physically possible to get all 4 inches in, and the anatomical diagrams on the Aneros site suggest that the slimmed portion is meant to sit within the area of the anal sphincter.
I think both posts are fundamentally correct. Unlike the earlier SGX & MGX models, the Helix, a "Next Generation" design, seems to adapt to individual anatomy and it leaves the excess length projecting through the outer sphincter. The Forum gets a post on this topic about twice a year. I thnk it works well as a 'one size fits all' toy.
concur, I have a good fit to the hilt but remember the anus is what 1/4 inch or so, maybe 1/2 inch, I'm uncertain.