For Google Pixel 4a Carbon Fiber Texture Horizontal Flip TPU + PC + PU Leather Case with Card Slot(Black) Tag-DVR Power Adapter Transmitter is powered by 1

Transmitter is powered by 1 x 12V 23A battery (not included)

not noisy and harsh

the blue light on the front of the keyboard flashes

General Compatible with Acer:  SF315-51G-52A8

For Google Pixel 4a Carbon Fiber Texture Horizontal Flip TPU + PC + PU Leather Case with Card Slot(Black) Tag-DVR Power Adapter Transmitter is powered by 11. Simple and easy, comfortable, easy to carry. 2. It adequately protects devices from the normal scratches, dirt, tear and wear. 3. Functional card slot, convenient for use. 4. Easy access to all ports and buttons without removing the case. 5. Made of PC + PU leather and TPU, it is tough and durable.