I have one that is on a QD mount on my Merkel 140AE in 450-400.
Does a great job, but had to have the knurled knob type, screw on/off as limited in space on ribs between the barrels. Mine is a Recknagel 4735-0123
You can get various mounting arrangements, but it has the same 'footprint' as the Noblex/Docter Red Dot.
Great units