Birzman Derailleur Hanger Configuration Gauge

- If your gear drop is slightly off, even the best adjustment won't fix bad shifting.

- With a gear drop adjuster, you can accurately measure if your gear drop is crooked and adjust it to perfection.

- It is easily screwed onto the gear drop at one end and the dipstick can then be extended to measure if your gear drop is crooked.

- It can be used on wheels that are between 20-29" in size.