The little tin included with the mouse comes packed with a complete set of interchangeable weights. It includes four 7g weights and four 4g weights, all neatly packaged with foam surroundings.

To access the weight storage you need to remove the external housing and a push-button releases a drawer where the weights are placed. You can have anywhere from zero weights to four weights in there. With the 4g and 7g weights to choose from, that gives you anywhere from 0-28g of extra weight in the mouse. You can also position the weights in the side or front or back, to provide balance or counter-weights to compliment the way in which you use the mouse.