The Good: Notched wheel allows for vertical and horizontal scrolling; unifying receiver pairs easily with other Logitech peripherals; power button conserves battery life. The Bad: Pricier than other mobile mice; no thumb buttons. The Bottom Line: The Wireless M505 Mouse is a good choice for anyone using Logitech's Unifying USB transceiver (which also works with its keyboards), but it's priced a bit high considering its limited button layout. The latest mouse in Logitech's seemingly endless line of input devices is the Wireless Mouse M505, a $50 portable pointer with an attractive design that comes in three colors: black, gray, and red. It's also one of the first devices to feature Logitech's Unifying technology, which allows you to connect up to six devices including keyboards and other mice to the same mini-USB transceiver. The technology promises to free up USB ports for other devices, but it also means that you're marrying into the Logitech family. The mouse is accurate and comfortable, but for $50, we're disappointed by the lack of thumb buttons. If you're looking for a no-fuss wireless mouse to throw into a laptop bag and run, we'd recommend the Microsoft Wireless Mobile Mouse 4000, which offers many of the same features and more for $10 less. \n \nThe Logitech M505 is similar in size and shape to the Microsoft Wireless Mobile Mouse 4000. It fits comfortably in both hands and there are slotted grooves in the clicker area for the ring and pointer fingers. The scroll wheel in the center of the two buttons is notched (as opposed to smooth), which allows for more precise scrolling through a longer Web page or document. The wheel is clickable as well, bumping the total up to three buttons. Unlike the Microsoft 4000, however, the mouse is missing the thumb buttons that we've grown accustomed to using as a shortcut for the "back" button in our Web browser. \n \nUnderneath the mouse, you'll find the laser tracking unit, an on\/off switch to preserve battery life in transit, and a release for the battery cover on top of the palm rest. The laser performed well in our accuracy tests, but we prefer the Microsoft 4000's BlueTrack technology that lets you ditch the pad and mouse on most surfaces that a laser just can't handle, including carpets and other rough and reflective textures. \n \nThe mouse runs on two AA batteries that are included in the package; it doesn't support rechargeable batteries, but Logitech tells us that the two alkalines will power the mouse for 15 months with help from the "smart sleep" mode that automatically switches to consume less power during long periods of non-use. \n \nThe mouse's USB transceiver is both the innovative selling point as well as the reason why this mouse is so expensive. If you're completely dedicated to the Logitech brand of peripherals, you'll be happy to hear about the company's brand-new Unifying receiver. This new technology lets you connect a single USB plug to six compatible mice and keyboards. Each device comes with its own Unifying receiver, meaning that you can conceivably leave them all plugged into several different computers at home and work. It also frees up USB ports formerly occupied by keyboards and mice. If you ever do need to take it out, the half-height USB receiver fits into its own compartment underneath the mouse for convenient storage. \n \nLogitech doesn't include any third-party software in the bundle, but it does offer Logitech SetPoint for Windows and Mac that enables the side-to-side scrolling as well as extra customizable functionality for the middle button.