MaxPar MH DE's are the only DE's available in in the MH format. Factory Label. Not any issues thatI have heard of.
The shielded arc tube is NOT for UV protection as many think. It is intended to protect the garden-space or users in case there is a arc failure. The arcs in the MH are pressurized, they are not in a vacuum like in an HPS. The lamps use to be able to fit in
Gavita HPS DE fixtures, but not any more.