King Arms makes the exact same sight for the exact same price.
While airsoft parts maybe out of stock, I'm sure you can find another retailer online whom you can source this item through.
I have been using this very same KA Vltor sight tower for 4 years now and it hasnt fallen apart of exploded on me yet. Its been through snow and rain and shows no signs of rust. So the least I can do is attest to its quality.