This device allows you to use the rifle and optic to dryfire practice in a very small area. With this adapter most scopes focus in the 11-15 feet range, depth of field is about 6”. By increasing your parallax distance you can sometimes increase that focal distance. With proper lighting you can use your scope at maximum magnification. Perfect for in the house, in the garage or a small backyard.
Use this device to practice different positions, balance points on the rifle, slung vs unslung, various support bag combinations. I have found the D.F.A.T to be extremely valuable in determining how small I can make my “wobble” with non-prone positions.
Usually shooters can get a good idea of their abilities and improvements by dry firing on known “MOA” size targets.