The A-Zoom practice round is a full aluminium cartridge designed to replace ammunition for dry practice. It feeds into chambers properly and a has a soft rubber cushion for the firing pin. The bright blue color makes it easy to recover after ejection as well.
These practice rounds are not limited to use just for dry fire either. They can be used in live fire to diagnose recoil anticipation (flinch) and can also be used to simulate a failure of ammunition. Both of these are a great use of dummy rounds in your live fire training.
As with any training, make sure that you are being safe and aware. Have fun!