I've only ever owned/tried this one from UTG.
Shop Leapers UTG Low Profile Combat Foldable Metal Foregrip, QD Lock | 4.5 Star Rating on 54 Reviews for Leapers UTG Low Profile Combat Foldable Metal Foregrip, QD Lock Best Rated +...
www.opticsplanet.com
(might be available cheaper elsewhere)
I bought it for use as a knee riser/hamster of sorts for field target but have found it works well for general use too. It's NICE for off-hand shots on pests (not legal for off-hand use in some of the competitions I participate in, although I wish it was). For off-hand use I let the bottom of the front grip sit on the heel of my hand, it makes it easier to lock that elbow into the hip.
The bottom unscrews and there's a compartment inside. Reminds me of one of the really nice Pellcan aluminum pellet tins, oring seal and all. I've never used the compartment on the front rest, but have considered adding junk/shot pellets to play with balance point on a gun or two, just haven't ever gotten around to it.
Kinda nice feature is that it folds up. Really secure mechanism, it has to be pulled down to lock and unlock, going either way, kinda nifty actually.
It is quick detach pic and I vaguely remember needing to do some minor grinding on the rounded cam area to make it fit the pic rails on my guns.
It's thick-walled aluminum and not necessarily light, but it's also not light-duty like some of the "composite" (PLASTIC!) ones that I've seen for much cheaper.
I'm not claiming this is the best thing out there in the front grip category, just sharing my thoughts on the only one I've ever messed with.