Registering Your Combination Kryptonite Support June 04, 2017 19:47 Updated Follow You can register your combination right on our website...quick and easy. Visit Key/Combo Registration.If you change your combination don't forget to contact us to update your combination in our system. Related articles Resetting Your Resettable Combination Lock KryptoFlex Combo Cable Factory Preset Registering your Keys Online Forgot Combination I have the Street F135/R14. What does the F and R mean? Comments 1 comment Sort by Date Votes Garciasanmiguel April 16, 2013 03:57 Please be informed that the Kryptonite Lock has a serial number 501088 and the spare key has the serial number SS67504 R 3. Please be informed that the spare key does not enter in the keyhole and I have not forced it. Your help is appreciated. Thank you 0 Permalink Article is closed for comments.