The best use for this harness is for a man to wear, since it has the pouch for the "boys".

I am a 5'11" 360 lb man with large thighs, and the size A just barely fit. I would say if you are larger than I then go with the B. I was surprised how many adjustments and how easy and fast it is to get on and off.

I am a beginner at harnesses, as this is my first. I think anyone could use this if you get past the price point. I was wary of spending so much money on this but glad I did because of the comfort. I really don't realize I am wearing it. It also provides plenty of resistance when thrusting.

I am using the harness with the Green Ballsy 7" dildo (had to chop the balls off to make this work).
My wife loves it. I happen to not be blessed with a large member, but this more than makes up for it.

The material is very stretchy but not itchy or scratchy. It is extremely comfortable. I have boxer shorts that are less comfortable than this harness. I feel this is the perfect material for this and it is machine washable. What could be better than that?

The adjustments on this harness are unbelievable. The waist has a velcro belt that is adjustable from it says 50" to 28". I am a 46" and it just fits. So I say 46" is the max. The butt or jock straps are extremely adjustable and do lift your butt. Also, on the sides are additional adjustments to further tighten as the belt velcro is impossible to get real tight.

This uses a O ring for the top and bottom. The Bottom is larger than the top. The bottom hole is used for the penis and the top for the dildo; a dildo will fit in both holes.

It appears to be compatible with all O ring toys I have found. I am using it with the 7" Ballsy Dildo and other than cutting the balls off it works great.

The waist has a velcro belt that is adjustable from it says 50" to 28". I am a 46" and it just fits. So I say 46" is the max

The harness worked just as advertised. My only surprise was the how comfortable it is to wear. It is very easy to adjust to put on and take off. My wife has a 28" waist and it takes no time for it to adjust to fit her when I take it off.

The toys are easy to install. It's the penis that is the troublesome part. There is a flap of fabric that hangs over the hole and getting it out of the way and putting the penis through is a bit challenging. I am on the small side (hence buying the harness) so that could be why.

The harness, once on, is like a part of you, so it was firm in all positions we have tried.