I had one of those but I gave it away. Can't use it on prairie dogs because they are too small and deer can't be seen far enough away to matter around here. 100 yards is a long shot in my woods unless I'm sitting on my range and they come walking down from the 200 yard line. It would be useful out west where you can see for miles, or for hunting in a bean field. It's still a useful skill to master and every shooter should understand the process.