If it's too small, follow this simple and not tricky step, it's ordionary step

For computer user
1. Press 'ctrl' button on your computer keypad
2. Scroll up the scroll bar in the mouse
3. Set the size you want to use

For laptop user
1. Press 'ctrl' button on your laptop keypad
2. While press it, you move your hand up or down it the right side of the touching mouse (in the right side, the very right side)
3. Set the size you want