To make sure you order the right size, you can measure your neck. If you are 38cm/15″ or less, you can order size I. If you measure 38cm/15″ or more, you can order size II. Necks are actually very much alike, no matter your regular size, weight or waist size. However, if you’re more comfortable with a loose fit, you can also order size II. This classic collar also comes in blue and with black buttons.