digital caliper for measuring things
$ 25.00
Like they taught you in elementary school, measuring stuff is easy and fun!
Now you have no good reason to buy the wrong size seatpost collar or post dumb threads on Reddit about what size tires your bike has clearance for.
• durable hardened stainless steel shaft with depth-measurement probe & precision ground jaws
• measures external, internal, depth and stepped dimensions up to 6" (152.4mm)
• displays in metric, decimal inches and fractional inches
• large LCD display is easy to read
• protective case & battery included
• accuracy: +/- 0.02mm/0.001 (-100mm)