The FX Radar Chrony is a great little tool but if you use one then you will know its short comings:
1 It needs rubber bands to fit it
2 It changes point of impact
I have designed an Air Tube mount for it which resolves these issues
Its all 3d printed with 2 little bolts to snug it up on the tube
Photos Show it on a Dreamline and Wildcat
Fitting is the same as for my QR mount (see my other items)