Flex 2-Charge 2-Blaze-Surge-One, Retired-Charge HR-Zip-Charge-One-Ultra-Recalled Force/ GALAXY S5- Linux through Galileo Project
Take a look at the Fitbit help site for further assistance and information.
I keep my products a long time (comparatively) so was curious about this as well, if I am investing now is it worth my investment. This was the information I gathered as part of my research "The features are identical between both versions. The difference is just the colors. The Special Edition versions undergo an additional process during their manufacture to apply the gold or gunmetal finish."
Hope that helps - Wanda