Amazon.com : Swagtron Swagcycle EB-6 Bandit Trail Electric Bike with Removable Battery and Dual Disc Brakes, Black, 20" Wheels : Sports & Outdoors
My daughter's Trek came with a 6-speed Shimano Revoshift SIS Index. It's a new bike. She can shift to higher gears easily but does not have the grip strength to shift back
Amazon.com : Inkesky RD-TZ31-GS 6/7 Speed Rear Derailleur with Direct Mount, Medium Cage, for Mountain Bike : Sports & Outdoors