Find Your Size

Apple Watch

When ordering a new Apple Watch band or bumper, it's important to know the case size to ensure everything fits your Apple Watch perfectly. Remember, sizing is based on your Apple Watch case size, not your wrist size.

One way to find your case size is by looking on the back of your Apple Watch device. However, the engraving is small and may be hard to read.

The easiest way to find your case size is by opening the Watch app on your iPhone. In the app, select "All Watches" in the top left corner. Then, you can easily verify your case size.

Fitbit

The easiest way to verify which Fitbit model you have is to look at the back or side of the device for the model number. It begins with FB and is followed by three digits. For example, Fitbit Sense has a model number FB512 and Fitbit Versa 3 has a model number FB511.

Here is a complete list of all major Fitbit devices and their model numbers:

Fitbit	Model No.	Type	Release Date
Fitbit Flex	FB401	Tracker	May 2013
Fitbit Surge	FB501	Tracker	October 2014
Fitbit Charge	FB404	Tracker	November 2014
Fitbit Charge HR	FB405	Tracker	January 2015
Fitbit Blaze	FB502	Smartwatch	January 2016
Fitbit Alta	FB406	Tracker	February 2016
Fitbit Charge 2	FB407	Tracker	September 2016
Fitbit Flex 2	FB403	Tracker	October 2016
Fitbit Alta HR	FB408	Tracker	March 2017
Fitbit Ionic	FB503	Smartwatch	September 2017
Fitbit Versa	FB504	Smartwatch	April 2018
Fitbit Charge 3	FB409	Tracker	October 2018
Fitbit Inspire HR	FB413	Tracker	March 2019
Fitbit Inspire (NON-HR)	FB412	Tracker	March 2019
Fitbit Versa Lite	FB415	Smartwatch	March 2019
Fitbit Versa 2	FB507	Smartwatch	September 2019
Fitbit Charge 4	FB417	Tracker	March 2020
Fitbit Versa 3	FB511	Smartwatch	August 2020
Fitbit Sense	FB512	Smartwatch	September 2020
Fitbit Inspire 2	FB418	Tracker	September 2020
Fitbit Charge 5	FB421	Tracker	September 2021