The Logitech M330 is a full sized mouse. For my personal preferences it is large enough to be comfortable in the hand, but still portable.
Here are the dimensions:
Mouse (height x width x depth): 4.15 in (105.4 mm) x 2.67 in (67.9 mm) x 1.51 in (38.4 mm)
Weight: 3.21 oz (91.0 g)
Please feel welcome to visit the Logitech website if you have and other questions, or if you would like product support.