The S&W M&P Shield is an industry standard, being one of the most popular concealed carry pistols ever. According to S&W over a million have been sold to date. But sometimes the factory 7rd and 8rd magazines don't give as much load volume as we like for a plinking session.  Laying some brass on the deck and with this 50rd drum makes us feel all warm and cozy.  These will only fit the single-stack magazine fed Shield 1.0 and Shield 2.0 pistols.  Sadly, it will not fit the M&P Duty pistols since those come with the wider double stack (staggered ammo) magazines. Nor will it fit the Shield Plus or Shield EZ pistols either. But we anticipate having drums for those soon......