Sunlite Digital Caliper
What seatpost collar size do you need? What's your seatpost size? Find out with Sunlite's Digital Caliper. Since it's accurate to .02mm and measures from 0-150mm wide, you can measure anything on your bike from spokes to your dropout spacing. It registers in inches or millimeters and is made from durable stainless steel. It even comes in its own protective carrying case.