Just wonna say I have been trying these lately and they ROCK ... better than Horse440's and Uli's .... try these, they are SUPenis EnlargementRB.
I simply get fully erect, clamp off with my hand at the base and than push against the glans towards the base the slowly jelq the clamping hand towards it ... I even hold stationary midway between to keep it engorged and I get a better pump than with the Horse's and it feels nice and spongy afterwards which is like I got in the old days with wet jelqs.