My own fault for buying something priced so low. Was unable to remove the one star. It shouldn't even have that. Only allowed 5 pictures per review. Several other areas of concern and discrepancies. I made this purchase in hopes that their product could surpass expectations in something so inexpensive. The saying; "you get what you pay for" usually rings true. But, every once in a while, something quality gets produced and sold at a fair price. I have some builds with an all top of the line, spare no expense approach. This build in particular is an attempt to procure the best value I can find in the vast amount of parts available, while coming in under the sticker price of off the shelf complete units. So, I rolled the dice and waited for them to come to rest. Wanted to see what they could do. You don't know til you know, ya know? I usually don't take the time to review products. This one is special. With today's CNC machining capabilities, this part is comically sub par. These are only external defects that can be seen. This upper receiver, if you want to call it that, may have hidden defects as well. Seeing the outside of it makes me question and even doubt it's integrity. The fit between this and the lower would not allow the take down pin holes to align. I didn't dare risk fitting any of my BCGs in it. It also looked like it would likely scratch or score any gas tube if I attempted to install one which, would leave stress risers on it. Many other issues that I don't even want take the time to write about. I actually just stopped looking after a certain point because, why bother. Feels very light compared to others I have. Makes me wonder if there is any porosity in the casting. I did not weigh it on a scale so, cannot confirm low weight. I placed it on an Anderson lower for comparison. Even the Anderson lower puts this part to shame. Anderson lower being another subject altogether. Not evaluating that here nor, did I take the time to do so in their case. Only mentioning them here to give an idea of what exact variables were involved. I am not about to even take this upper in the same room as my other lowers or builds due to possible contamination of said parts. Aside from the poor fit, it is not aesthetically pleasing to my eyes at all. While looks are not as important as practicality, fit, form, and function, appearance matters to some. It does however, fit in my 30 gallon trash can very well. Even begins to look better once in the trash. It's as if it belongs there. To express my competence in this evaluation, a little background on me: I am an aerospace structures technician and have moved into inspection. This is after twenty years as a technician and four years in Inspection now. Inspection of machined parts is what I am trained to do professionally. Not trying to toot my own horn but, I would like knowing what experience and/or qualifications someone has when taking into account their opinion or evaluation of something. Junk parts find their way into every industry. This is why we have incoming inspection. I would not allow this company's parts to be installed on aircraft or children's toys for that matter. They should either go back to the drawing board and start from square one with better equipment or, shut their doors for good with a lock purchased from a reputable company. I wouldn't trust any lock they manufactured themselves. As we say in aviation, this POS ain't gonna fly. If I were in battle I would want my enemy to have a better upper receiver. I think everyone deserves a fair chance. AT3 Tactical sells many products of varying quality. I do not think this product necessarily reflects directly on them. I do hope they read this and delve further into it. For their own good and for that of others. Hoping that this review saves someone the trouble. I would have liked knowing beforehand and avoiding this. Well, I have spoken my token, that is my two cents. This ugly girl ain't sittin' on top of my boom stick.