ELECOM EX-G Wireless Mouse L Size M-XGL30DBSKWH A mouse developed in collaboration with doctors for an exceptionally comfortable grip. - Brand: ELECOM - Model Name: EX-G - Size: L - Wireless Connection: 2.4GHz Power Source: Battery-powered (1 AA battery) Connection Type: Wireless Other: Silent This mouse is designed to be held at an angle to reduce strain on the hand. As shown in the photos, only the mouse and the wireless receiver are included. Also, as you can see in the photos, I noticed discoloration on the underside rubber of the mouse near the base. I tried cleaning it thoroughly, but the stain seems to have soaked in and I couldn't remove it. I've also taken a photo of the battery compartment, and I don't think it's from battery leakage. It seems to be a stain on the rubber or whatever material it is. Regarding functionality, I've confirmed that it works without any issues, including a web-based mouse check. Since I'm a bit concerned about the current stain, I'm offering it at a lower price. If you're concerned about hand fatigue, or if you don't mind the stain and are interested, please consider bidding.