Microsoft SideWinder X8 Mouse
This came out in 2009 June.
Microsoft Sidewinder X8 mouse. Wireless.

- Play and Charge - Up to 30 hours of active gaming on a single charge, or use the play-and charge cable for non-stop action.
- BlueTrack Technology - World's most advanced tracking technology for gaming with image processing of 13,000 frames per second.
- 2.4 GHz Wireless - Built for lag-free play.
- DPI Switching - Instantly switch sensitivity between high, medium, and low with one click.
- 7 Programmable Buttons - Customize 5 programmable main buttons, plus left/right tilt, to your preference.
Additional Features:
- LCD Display - Quickly view DPI settings and macro-recording icons on the mouse.
- Replaceable Mouse Feet - Choice of 3 different materials for glide preference.
- 7 Programmable Buttons - Customize 5 programmable main buttons, plus left/right tilt, to your preference.
- Macro Record - Easily record macros while in game with the dedicated button.
- Specs:
- Resolution: 250–4000 dpi (BlueTrack™ Technology)
- Image Processing: 13000 frames per second
- Max Acceleration: 75 G
- Max Speed: 120 inches per second
- USB Reporting: Full-speed, 500 Hz
- Feet: 3 sets of different mouse feet (for glide preference)
- Wireless Play: Up to 30 hours
- System Requirements
- Windows Vista®/Windows XP
- 100 MB
- USB Port
- CD drive

All Microsoft SideWinder Series 〔see Microsoft SideWinder Mouse Series〕 have 1 scroll wheel, 3 instant-change DPI buttons, and at least 5 programable buttons. But the X8 has 7 programable buttons, counting the left/right nudge of the scroll wheel (aka tilt).
The X8 is wireless, all the others are wired. The wireless of X8 is actually quite advanced. It uses and comes with one standard AA sized rechargeable battery. It has a magnetic connector, so it snaps onto the mouse when you need to connect the charger, and you can use it as a wired mouse while it is charging. It also features a new blue laser technology, for a 4k DPI tracking. But even if you are a hardcore gamer, any DPI over 2k is basically useless. 〔see What is Mouse DPI? Does DPI Matter?〕
The middle 3 red buttons let you change DPI by a single press. They light up. For example, on the X3, the top button is 2000 DPI, the middle 800, the bottom 400.
Changing DPI is a great feature. For gaming, you want fast turning, but when you are aiming at a distant target, you want less sensitivity for precision aiming. This applies for non-gaming work as well, such as working in 3D Modeling Software .