SUNSHINE SZ Ultralight MTB Cassette 11S 12S 10S Mountain Bike K7 11V Bicycle Flywheel Alloy 12 Speed HG for Shimano M4100 5100

The reviewer mentions the SUNSHINE SZ Ultralight MTB Cassette as part of their 12-speed drivetrain setup. They describe it as a cassette from the brand Sunshine, which can also be found in Western online stores. The cassette is paired with a 32-tooth chainring in the front, providing a 11-52 gear ratio that the reviewer finds excellent for climbing steep gradients (up to 18-20%). They note that the shifting performance has been flawless without needing adjustments, and the cassette's ratio is perfect for a 1x drivetrain in mountainous terrain.