I have to press the "b " key much harder than the other keys.
Cheap product. Probably made in China. You have to press the "b" key very hard to work. After a month, the pause button will activate itself. Will spoil the whole impression. PLEASE DO NOT BUY, only take the original.
Pros
quick connector. This left single Joy-Con can wirelessly connect with your Switch. You can connect it to the switch or just press the SYNC button to connect the console.