I'm sorry. I didnt have time to explain . No not a LRF , but. Laser as in a red dot laser . Mounted above the scope it needs to be at least a couple of inches , well the higher the better. If you rig the laser to be dead on you're cross hairs at your zero range , then when the target is closer the laser dot will be above the cross hair , and if its further away , the laser dpt will be below . Very simple , but hard to explain . When I'm at the computer later , I'll see if I have some more info to help