There are good quality and very poor quality copies of the M-51 Engineer Field Bag out there. I think most everyone who has one likes the design of the bag, but the quality of construction varies to an extreme degree. The black "M-51 style" bag that I bought online fell apart in a few weeks, but the old olive drab one I got at a surplus store has lasted for many years bouncing around in the back of the car, being carried around, and holding more weight (in tools) than it was designed for. Be careful on this one!