Beam me up, Scotty!

I know that mine is a moderate to severe case of age-related cultural disorientation, which explains why, when I look at shop windows like this one, I feel as if I have descended into an alien world where there is so much going on that I neither know about nor understand.

This tattooist parlour (or is it a surgery?) provides a fine example of products and activities that are a total mystery to me.

Tattooing I know about and can just about understand, but what I cannot fathom is the popularity and extent of the practice almost, it seems to me, amounting at times to a culture of widespread self mutilation. As an un-tattooed person I am very much in a minority it seems.

My mind boggles at what this place is advertising. What on earth is a "tunnel". Where is one located?; where does it go to or from? and how long is it?

In my ignorance I have some wild fantasies and imaginings, all of them entailing painful treatment of unmentionable and delicate body-parts!

What is a"stretcher"? and what does it stretch? Here, again, I visualise the stretching of parts of the anatomy that were never designed for stretching, ditto with "belly bars".

As for "nipple shields" - well I thought these might have been popular with the Amazons, who amputated breasts, but what they are exactly and what their attraction is in a 21st century culture I simply cannot comprehend.

I am truly a stranger in my own land, ignorant of the popular culture, bewildered and alienated. HELP!!!!!!!!!!!