I'm confident these are the same as the Clarks M4 that kind of made it to market. I got these Meroca brakes to go on a budget trail hardtail, $60ish CAD off AliEx. They arrived with one of the levers very gouged up. The seller only gave me a couple bucks discount. I hit the gouged lever with some black paint and it looks better, but can still see the deep gouges.
The pads are the same size as the shimano 4-piston brakes. The original pads were pure trash - the backing plate and pad material were rusty. I tried them out after sanding and IPA cleaning, proper bed-in, etc ... total suckage. Popped in the Kingstop Taiwan semi-metallic pads (comparable to Shimano resin pads) and they are good now. I shortened the rear hose and used a shimano olive and barb just fine. I also had to swap levers right to left. I'm confident these are the same as the Clarks brakes and will use that bleed procedure. The lever feel is a bit meh but usable, i think the lever swap introduced some air so I will need to bleed them and see if they improve.
Basically after some screwing around, they're pretty good. Decent 1-finger braking. The calipers actually look very nice in terms of quality, finish, etc. The levers ... look kinda budget and a but clunky. I will say, the lever ergonomics are actually pretty good.
For the price, I would buy them again. Shame about the damage to mine, but it doesn't affect performance.
PS - for good brake pads and hydraulic fittings at half the cost of Shimano, I've had great luck with the Kingstop store on AliEx.