Studs are small charms that simply pop into the holes of your smartwatch bands for a snug fit.  

classic and infinity bands from Fitbit

• Our Fitbit studs are designed for Classic and Infinity bands from Fitbit. These bands have rectangular holes; the back of our Fitbit studs is rectangular. 

third party bands

• The holes in some third party bands may be a different size than the holes in bands from Fitbit. Make sure your stud fits securely if you have a non-Fitbit branded band.
• We are not able to guarantee fit or warranty our studs on third party bands because even if they look just like Fitbit bands the material of the band and size of the hole may vary and affect how securely the stud fits. 
• If you have questions about a third party band, please email us at support@bytten.com.

sport bands from Apple & bands with round holes 

• For older model Fitbits with round holes (e.g., Alta & Alta HR Classic bands) and Apple Watch Sport Bands please visit our collection here. (ADD URL)