Park Tool Wheel Alignment Guide WAG-5

For a wheel to perform properly, it is important for the rim to be centered between the locknuts of the hub, or “dished.” The WAG-5 accurately gauges dish on 24 x 1-38" to 29" wheels (ETRTO or ISO sizing of 571 to 630). Disassembles quickly for storage or travel and works with all hub types.

Warning: California Proposition 65 

https://planet-cyclery.myshopify.com/pages/warning-california-proposition-65