Stumbled across Arm or Ally while doing my latest AR build (height of Covid crisis). I was building a M4E1 enhanced, however; AERO has been out of stock & backorder in some cases into June, July, Aug! Happen to stumble across Arm or Ally while desperately searching for a M4E1 enhanced upper. Not only did Arm or Ally have it in stock, but the price was right on! Arm or Ally is a smaller outfit from what I gather, but they are committed to service & customer satisfaction. They have a little disclaimer stating that due to Covid, their small operation, and slower shipping due to Covid that it may take up to 10 days to ship item. This was not the case. I believe I received the upper about a week after placing the order. I am super happy with Arm or Ally, their service, and I will be shopping with them online again. Happy customer Mark Taylor