FIND IT HERE! https://doublemdefense.com/product/vx-precision-qr-ext-30mm-mount/ 

This quick release cantilever mount is designed for mounting telescopic sights with 30mm tubes onto a flattop style AR-15 rifle. The offset of this cantilever mount positions the scope in a forward location, providing correct eye relief and head placement when used on an AR-15.

 

Weight 8.9 oz
Center Scope Height 1.45 inches (37mm)