As a very wise person once observed, men can be so squeamish. That's why we call our iteration of this perennial CBT favourite "Pleasure Gates", instead of the more usual "Gates of Hell". That and the fact that the device is actually far more pleasurable than hellish.
Sure, it's really tight and constrictive. Yes, you will be engorged to the brink of painfulness. Yes, your cock will turn a livid purple, crisscrossed with sharp, angry veins. But look on the bright side!
Pleasure and pain are fluid interpretations of sensation, and are highly context dependent. In a positively sexually charged situation the body is awash with freakish chemicals, with really long names. In those circumstances - reasonable to assume if you are wearing a set of Pleasure Gates - the brain processes physical sensations differently. That's why someone who wouldn't hesitate to call your parole officer if you bit their nipples during a team meeting, positively purrs when you do it in the heat of the moment.
Treat yourself to a well lubed oral or manual massage whilst encased in a set of Pleasure Gates, and you'll see. What the primitive commuter brain perceives as an outlandish act of inexplicable self harm is recognised by the more evolutionarily advanced pervert brain as a source of exotic pleasure. The fact that you'll see while being reduced to particles of quivering orgasmic jelly is, of course, a bonus.
For the nuts and bolts of strapping on a set of Pleasure Gates, we need to return to the meat and two veg metaphor. First, the Brussels sprouts go through the large ring. The soft, but soon to be mighty, knackwurst follows them through and continues on through the smaller rings. A bit of lube in the right place is always helpful in this situation. I've pitched this blurb mostly for the newbies, the sceptics and the nervous, for the very good reason that those who know, know, and don't need the Gates explained. Remember, Pleasure Gates have to go on while soft, otherwise they will not go on at all. Yes, it is a squeeze, that's the point. No, you are almost certainly not too big. Please don't try to use them for penetrative sex, that's not going to work.
And we do recommend, if you are new to this item, that you consider the rubber version!