We had one of these about five years ago. These are fine if you only need them for occasional use. We always had a problem with the blast media leaking everywhere. Since then, we've moved on to this dual door cabinet from Raptor Blaster , and though it may not be a bargain basement deal, was...
You should be able to order a reliable blast gun here: https://www.idsblast.com/sandblasting-supplies/category/1358
or here: https://www.raptorblaster.com/parts-accessories/
Use a ceramic nozzle if you plan on blasting with glass beads, use a tungsten carbide nozzle if you plan to use aluminum...