Here is a well designed training device. It is simple in its design yet well suited to convey the all important message that a slave boi is just a chattel. Sir has no concern for its comfort or discomfort. And equally as important, its job is to suffer silently and not bother Sir. If Sir has to continually waste his time on it by continually inflicting pain and discipline, then slap would actually have some control by using Sir's time. This rig puts it in a position of continual discomfort.Either the arms cramp and ache or it lowers them for relief and it tears at its tit clamps. So it goes back and forth. Meanwhile Sir is free to do whatever. Sir can go out, nap, screw some other slave in front of it or even have it suck him dry. Such a lucky slave to be enjoying this exquisitely designed training.
He hasn’t worn a shirt since Memorial Day. Always has his torso bared and available for toying.
A hard body comes from hard work
Dumb Down, Muscle Up, Show Off 
“Nipple Nightmare” (2004) from Zeus Studios.
Muscle-hunk Rob Cryston takes muscle masochist Blade Weston's nipples to hell and back with clamps, weights, chewing, stretching, and flogging.
Bits