The smaller ones are commonly known as the Chid/DuD/mini-DiD "clone", and are being sold as the Griffin ($22), the Vulcan ($19-21), COV Gen1 ($12), MOV V3 ($20). I have 5 of them & like 'em a lot. Set up at ~2Ω, they're great on Twists.
But better than that, IMO, is the Chobra (Cobra clone), a mid-size
rba. I have 3 up & running right now. I know DV sells them for ($25). I bought mine in a co-op for less tho'. I run these on my big batt mods, as well as the AGA-T.
The Big ones you see posted lately are the AGA-T, but it is a hefty beast and not suited for smaller PVs - again IMO.