Well I can only say what a fantastic peice of kit this is.
Its the handheld Zeiss Victory 8x26 PRF (pocket reange finder) with BIS (ballistic Intelligent system).
Let me explain you take the charts and match your load/zero and then program the unit to that cartridge (dead easy 1 button).
Then when you range your target the range is displayed in yards or metres the a second after another figure flashes up telling you a hold over figure in inches or centimetres.
And it works.
This morning a fox was rumaging around and with no way of getting closer I decided to let the client have a go.
Using a 6.5x55 with slow 156RN'sit was no mean feet(rainbow trajectory).
Having already programmed the PRF I ranged him 189 yards then it flashed H5 indicating 5 inch drop, I said aim 2 inch over the foxes back and he fired.
I also in the course of the morning ranged a hare at 588 and a roe doe at 468, 592 (107 inch drop ).
And optics so clear you could leave your bins at home.....