Pascual, you can use a angled foregrip, but a vertical foregrip changes your M&P15 pistol into a short barreled rifle and would require a tax stamp. I use a strike industries hand stop/vertical foregrip on my Ar15 pistol. It's mlok so it will attach directly to your handguard. Here's a link to the one I use if interested. Hope this helps, link here............. budsgunshop.com/product_info.php/products_id/31045/strike+link+curved+foregrip+ar-platform+black+aluminum

be careful modifying your ar15 pistol like james stated the addition of a vertical foregrip makes it a short barrel rifle and will require you to have the proper paperwork for a NFA item " A SBR, or short barreled rifle, is a rifle with a barrel length less than 16 inches or an overall rifle length of less than 26 inches. Having a length shorter than either of those classifies a rifle as a short barreled rifle, and falls under the NFA rules, which means it needs a $200 tax stamp along with some paperwork, fingerprints, and photo to legally own."

Pascual, you can legally use an angled foregrip but not a vertical foregrip. I use the Magpul AFG-2 : budsgunshop.com/product_info.php/products_id/1138/magpul+mag414-blk+afg-2+ar+platform+black+polymer ---------------------- You will need an M-LOK Rail to attach it here : budsgunshop.com/product_info.php/products_id/714019712/seekins+mlok+rail+section+5+slot --- Cheers and stay safe!