Looks like a great price as these are going for well over $10 on ebay, banggood, gearbest, and even other sellers on aliexpress. Looks like a very handy little keyboard with pretty good reviews.
Specification :
Connection: RF 2.4G wireless connection
Power supply: 1.5V 3A battery 2 (Optional 400mA/800mA lithium battery)(Not included)
Operating voltage: 3.3V
Wireless Transmit Power: 2dBm
Receiver sensitivity:-85dBm
Color:Black
Touch pad: about48x38 mm
Dimensions: Approx.146 x 98 x 19 mm
Weight: 118 g
Package weight:138 g
Bought one to give it a try if it doesn't work ill just throw it away no big loss lol