At international level there are two audio aiming systems approved.
- The EcoAims VIS500 is the system I use for air rifle. I think its simplicity combined with how well it works is what makes it my choice. Having an internal battery it only requires the shooter to connect earphones to get started. There are mechanical adjusters for sighting corrections and a couple of settings which can be tweaked via software on a computer, although these need not be tweaked to be able to use the device well. There is also some training software for the computer which allows training without pellets, however for serious shooters a Scatt trainer may be preferred for electronic training tracking.
- The VIASS Pro was designed by a VI shooter who felt the offerings available did not meet his needs. The big advantage of this device is that it can be fitted to some air pistols such as a Walther LP400. Also the VIASS has many settings which can be adjusted via software on a computer and the sighting adjusters are electronic push buttons. Whilst there may be advantages to the customisability of the VIASS, I do find at times it can be slightly overwhelming and it may not be obvious what is the optimal settings for a user. Again the VIASS has training software for the computer for pellet free training.
I realise for those who are not looking to compete at international level, the cost of these aiming systems may seem quite high. For those they may want to look around for alternatives. One worth mentioning is Kedok which aims to make an affordable aiming system. However if taking this route, be aware that should you ever want to go international you will need to then buy an approved audio aiming system and learn the tone of that new system.