Blue 2.4GHz Wireless Battery powered Optical Pen/Mouse Adjustable to 800/1200/1600 DPI $5.47 AC

https://www.amazon.com/dp/B018E62O4G
Uses 1 AAA battery and includes low voltage warning to replace when low.
Amazon price is $13.69 use coupon M628VX43 to bring price to $5.47