I have experimented for years with a simple hand held tens machine. It was used initially for its purpose, for the relief of back muscular pain. It was my own twisted mind thinking I could use it for pain/pleasure. At first, I used the rubber adhesive pads that came with the unit, after a while, the adhesive wore off so I had to improvise. I have used many items from metal champagne cork covers, these fit over the glans particularly well, to a couple of silver - not silver plate - napkin rings. Being in the antiques trade, these things come along with great frequency - excuse the pun. I removed the adhesive pad, cut the coating on the cable and wrapped it around each of the napkin rings. These were held in place on the outside of the ring with elastic bands. The slightly larger ring slipped down to the base of my (erect) penis, this in turn pulled the foreskin back. The other, which was slightly smaller, slipped over the glans and sat neatly under the glans, resting hard up against the flare of the glans corona. Both of these I used some simple hand cream to form a contact.Switch the machine on and let it go, whether a throbbing pulse, a gradual increase and decrease in pulse, or a constant pulse.I replaced the 6v battery with a 9v, just for a bit extra punch. I have experimented many times with all sorts of cable, wrapping around and over the glans, cutting across the meatus. I generally start with a gradual pulse just to get my penis accustomed to the rhythm, I increase further, this makes my erection even more, and enjoy watching the glans swell and expand in rhythm to the current. After a short while, I turn the machine to constant, increase the current to max, and wham! Quite an explosive orgasm - not spurts but more a long copious dribble of sperm. Great fun. What I have always done is to make sure all contacts are clean, sterile and washable. A tens machine can be purchased on many bona fide medical on line sites, can cost around £100 or so - great fun, and they can ease back pain too!