Previously known as the Logitech Optical Rollerball.
This is one of the smallest rollerball devices and although isn't very suitable for those who lack good fine motor control, it has proved suitable for clients with restricted movement and muscular weakness caused by conditions such as Muscular Dystrophy. The device fits well in the palm of the hand and as it's symmetrical it can be used left- or right-handed. The ball is designed to be operated with the tips of your fingers and it's quite easy to inadvertently press the left/right buttons on the sides whilst doing this.
The device has recently been re-branded as the 'Marble Mouse' and looks a little funkier in silver. The ball is optical and can be pulled out, cleaned and popped back in (but is therefore easily lost and I have seen many pupils pull the ball out and roll it along the floor).
This is a stylish and well-made device. It is a lot less expensive than some of the bigger rollerballs, but it's far less versatile and can be difficult to control.
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