For me, the biggest red flag is anything that claims to be “universal.” Whether it’s holsters, mag carriers or slings, if it’s marketed as fitting every gun ever made, it usually ends up fitting none of them properly. Another thing that gets me is budget optics with a tactical twist. They come with flashy marketing and cool names but the zero tends to wander if you so much as sneeze. I’ve had a few that were decent for casual shooting but there’s no way I’d trust them for anything serious.