Think it's "TPH" 122. That's the MacKissis I have that I use off my 18.5
hp 4010 3 ph.
It's GREAT and so easy to work on (compared to a beastly TroyBilt I had for a few years). Removing the chipper blade is a breeze, as is rotation or changout of the beaters. The spacers on this machine between the beaters don't get beat up like they did on the TroyBilt.
I use mine a lot, especially to grind up about 100-150 bags of leaves every year for my garden. Also use it for all the fallen brush, up to 3 to 3.5" OD. Keep anything bigger than about an inch out of the shredder hopper. Bigger stuff will put dents in the lightweight housing.
Ralph