baaletc extender band for fitbit flex/ 2 & fitbit alta fitness tracker wristbands - designed for larger size wrists or ankle wear, 14mm (width) x 115mm (length), black - Walmart.com
Fitbit Flex 2 Bands Replacement Wristband Accessories Classic TPU Material Sport Strap for 2016 Fitbit Flex 2 Fitness tracker(Large, Black) - Walmart.com
FitBit Flex Fitness Band - First Look, Unboxing, Setup and Features - YouTube