What the hell is that ive never herd of a portable grav if i saw a pic id probly know how to use it though post a pic
---also sold here in the grasscity store,(pg 2 of novelty pipes i think) but not with the grinder package deal, or the wood grain....it looks pretty simple. put the weed in the bowl, pull up on the top of the "bukket"while applying fire, and then remove the bowl, place mouth on hole, and press top/bottom together rapidly- then repeat many times
I have one... It works just like it says on the site dopey_won posted... You don't have to push the bottom back up though, you just inhale and it comes back up pretty quick... Fun little thing...