This Fitbit Flex Wireless Activity and Sleep Wristband drops from $99.95 to $79.96 with code ANNV13 at REI.com for REI members only. With free shipping, this is the lowest total price we could find by $20. This Fitbit tracks steps taken, calories burned, hours slept, and more. Sales tax is charged in most states. Note that only REI members are eligible for this discount. Sign up here for $20 to receive this discount, 10% back annually on your REI purchases, and more.