Installation of the batteries should coincide with the association of the keyboard and mouse to the receiver. The receiver is inserted first, and then while holding down the ESC key on the keyboard, place two of the AA batteries into the bottom slot. The first battery must be slid all the way to the right of the opening to make room for the second. A tiny green LED in the receiver will flash once the keyboard is connected and then the ESC key can be released.
The mouse is setup similar to the keyboard, although since it possesses an on/off switch there is no need to hold buttons depressed while inserting the battery. Once it's in place and the cover reinstalled, simply flip the switch to either the L (800dpi) or H (1600dpi) position and the mouse should associate as well.
There were no problems getting the RKM-1600RF installed and setup, although I had to make a little extra room on my keyboard tray for it due to the increased width. I run my other laser mouse at 800dpi so that's what I set the new one for, the "L" position on the bottom switch. As I mentioned before, the mouse has a very light touch on both primary buttons, and that coupled with the short body caused me to be a bit "hair-triggerish" with my clicks. I found the side buttons to be the exact opposite of what I am used to, the front button is used as the "back" and the rear button is the "forward". Finally, due to its small size and light weight, I found myself greatly exaggerating the mouse movements, whether gaming or just using it in Windows.
The keyboard has a very similar feel to a laptop. With its slim keys and short strokes, I often found myself getting double characters out of a single key press. This does make the keyboard a lot quieter as there is not as much clicking and clacking coming from the keys as what you get with a typical keyboard. One thing I found myself constantly missing was the backspace key, as I am not used to one that small. Also the backslash is completely out of place from what I am familiar with.
Rosewill claims the wireless range on the RKM-1600RF is good up to ten meters and I put that to the test. I took the keyboard and mouse to the other end of my house and was still able to use both without any problem, even without line of sight. I later measured this distance at more than thirty feet, so they are right on the money with their stated specs. The FHSS and AFH technologies prevented interference from other wireless signals in my house, including an extensive 802.11g network and several 2.4GHz cordless phones. I also tested how well the laser mouse works on alternate surfaces and am happy to report that it will function well on just about anything; a wood grain desktop, the carpet, the couch cushion, even the leg of my jeans.