You can expect a total of 15 customizable controls, a dual-mode scroll wheel and, as is more common with Logitech’s mice these days, plenty of battery life. You’ll get ten days’ worth of battery using Lightspeed (shorter than the 21 days of the G603, but it’s more complex), but a whopping 5.5 months on Bluetooth — and both need only one AA battery.

The G604 arrives later in the fall for $100. That’s decidedly more expensive than the $70 G603, but it’s evident Logitech sees this more as a step up than a straightforward replacement.