One of the accessories is something that you normally don't see with the normal mouse you purchase, and that is a a slot cover that allows you to wind the excess cord from the mouse around the hooks located on it to make the desk bit neater.
The other accessory that comes with Sentinel Advance is the replacement Teflon pads which you can place on the bottom of the mouse after you have worn the affixed feet down from hours of usage. Other mice will charge you up $15.00 for a replacement set of feet.