I'd never heard of this one. I thought LAW Tactical had a monopoly on the folding adapter market
I installed the Sylvan Saturday and it took me a whole 5 minutes. Super easy and a cheaper than the LAW Tactical. Plus they're in stock at: https://www.masdefense.com/SYLVAN-ARMS-SIDE-FOLDING-STOCK-ADAPTER-ARH300-p/arh300.htm