Knock Down Reset Target

this is the first target I made and I have stuck with is ever since for shooting at in my room or anywhere when using a K'nex gun or a bb gun. To use it, shoot at the top target to knock it down and then shoot the bottom disk to reset the top one. I got the idea from an air rifle target that I used to practice on at a club I used to shoot for and now I decided to use one for something a bit less powerfull.