I lost my usb receiver, Yvonne at customer service was AMAZING and was able to allow me to buy only the receiver so that I didn't have to re-purchase the whole mouse

Then I accidentally broke the nano receiver and AnkerDirect replaced it for free and within 5 days

The mouse itself is well made, the previous mouse's receiver is fragile

I changed the batteries twice before chalking it up to a faulty receiver

And I received the best customer service when I lost my USB receiver

Not only is this a great ergonomic product, ANKER provided the most OUTSTANDING customer service when I lost the receiver.

The wireless receiver crapped out after a month, and I had to return it

Now that I've had a chance to use the mouse, my thoughts are that a) the plug and play USB dongle is very smooth, and I haven't noticed any input lag, b) the material is a bit slippery, which causes me to grip the mouse slightly tighter than I would normally and exert more effort to depress the mouse buttons/reach the scroll wheel than I would like c) it tracks very well on every surface I've applied it to d) the slipperiness and effort involved in making clicks means that it can be hard to do precision work, as (I at least) need to have a small adjustment in the position to make a click

I purchased this & I no longer have pain.

Disappointing as I really like the ergonomics of it.