Waited months for this to ship and.... - Luth-AR .308 Magazine Catch

So I waited months for this to arrive. No that isn't an exaggeration. Finding a legit mag catch that is made specifically for a 308 and is therefore longer than a mag catch for a 5.56 lower is quite hard to find. Just my luck when I saw this item from optics planet! Except what I got was a mag catch that is the exact same dimensions as a 5.56 mag catch. TLDR: this will not fit a lower if it is wider than a standard 5.56 lower. It definitely won't fit a 308 polymer lower. If I can include pictures of the mag catch side by side a 5.56 mag catch I will include those as well. Last thing I want is anyone else to be duped into waiting let alone paying for a product they can't use for the intended purpose.