Umarex Smith & Wesson M&P - BB - 4.5mm
The S&W M&P is not going to take any awards for material and build quality, it's mostly plastic and feels a bit light in the hand. It is however a good replica appearance wise with everything in all the right places including the Smith & Wesson licensing. Factor in the drop free metal magazine and fiber optic sights and you have the making of a decent BB replica.