If you run an Eotech on any of your weapons then you need this. If your Eotech goes down, the lever system allows you to quickly remove the unit and get it out of the way so that you can use your backup iron sights (otherwise you have to use a screwdriver or a quarter to remove it). You can quickly reattach it and it will still be zero’d. They usually go for $85. They are on sale (how long I’m not sure) for $19.95 delivered. This is one of those deals that I’m always talking about.