You can pump up your prick with a cock ring or a shaft ring. They work on the same principle. A lot of guys like to wear a cock ring near the base of their shaft but above the balls (as opposed to the traditional positioning of a cock ring below the balls and snug up against the pubes, see the picture below). When worn here, it is known as a shaft ring.
A shaft ring needs to be worn snug enough that it doesn't slide off when you are flaccid. Or, if you are just wearing it for sex, slide it on with lube after you are hard. Like a traditional cockring, it restricts blood flow causing your dick to get fuller and thicker. Be aware that if you use too much lube it will slide right off again though. This is why I prefer to wear one that is a bit snugger (snug enough to stay on when I am flaccid). It gets tight when I get hard but I've never had any pain from wearing one that fits even when I'm flaccid. In fact, I find the added pressure pleasurable.
The hard dick pictured above is wearing an M2M stainless steel glans / shaft ring. Depending on the size of your dick you can also wear a Titan .4 brushed 1 1/2" shaft ring or one of gear essentials' larger glans rings.
Enjoy the pump!
gear essentials…Sex is Better here! ENJOY!
WHERE TO FIND IT: M2M Glans Ring: http://gearessentials.com/collections/glans-rings/products/glans-ring-stainless-steel
(Photo re-blogged from Tumblr.)