I bought this one off Ebay.
View attachment 1715751538 BLAST CABINET METERING VALVE HARBOR FREIGHT SANDBLASTING METERING MEDIA VALVE | eBay
I think it does help with the delivery of blasting media. My issue is that the slope on the floor of my blaster is shallow, so the media doesn't funnel very well into the bottom hole.
But, I would say it does help. Just be prepared to make some mods to your blast cabinet.
