More info? Xd / HG? Size? Speed? Cost? Link? Please....
It's a ZTTO 12 speed HG but you can get them in XD too. They also make 11 speed cassettes. Google.
Yep BK is correct. It's a ZTTO 12 speed HG, in 11 to 50, all steel except for the 50, and it weighs 360g and cost $300.
I've just installed it with a new NX chain and yeah the rear end of the bike feels much less like a paper weight than it did with the 620g NX cassette. Reducing unsprung rotating mass by over a quarter of a kilo, is heaps and just picking the bike up, it feels even front to back now.
The back pedalling is not fixed, testing it on the stand, with the 50 tooth cog derailing 95% of the time with usually about one full reverse rotation, sometimes a bit over a half rotation, sometimes weirdly not at all. The largest steel 42 tooth, almost never derails... to do it you have to spin the crank backwards pretty hard. The smaller gears, not at all. I'm no expert, but I think I can live with it. I can't ever remember back pedalling while spinning up a steep pinch in granny, it's just not something I do. Regardless, I just hope it doesn't end up catastrophic failure, deep in the bush on a 40 degree day, with water at a premium.
I've only tooled around on the street, just before the rain hit, and was only focussing on its shifting and back pedalling, and I could not get it to derail at all. It shifts gear very well, as good as the NX, I'd say.
Anyway, hopefully the rain will eff off, and I'll be able to hit some local trails.