Not entirely sure what it is, but i think it's something that they sit on and it vibrates and it's hands free.
It was pretty much popularized when carmen electra rode one on the howard stern show. Damn shes hot. But ya google it. Many women love it.
If you go to their website it tells you that you send the measurements of your dick and they custom make this receiver for your dick to fit in
I think my wife would like one. Now, she straddles a couple of pillows and rides her vibrator. It's fun to watch. One of the benefits of marrying a chronic masturbator. (That's not a real word, BTW.)
Sybians are great, and VERY expensive. A working-class lady might try the CiciLove saddle, which works with the excellent & powerful Hitachi Magic Wand vibrator. The little saddle kind of supports the vibrator, and the lady sits on it. No penetration, but a wonder for the clit.
I watched a video recently of a woman on the Sybian having a series of sustained 10 minute orgasms. She couldn't walk afterward, but she'd take a break and hop back on. A male version doesn't sound like it would be an edging tool, just a mad rush to a screaming orgasm.
Oh, one more. Here is the video I mentioned above... http://www.tube8.com/teen/caroline--sybian-full/14732/