Mountain Bike Rear Derailleur Shimano Tourney TZ31 6/7/18/21 Speed Direct Mount | eBay
Shimano Fd-Ty300 Bike 6/7 Speed Front Derailleur 18/21 Speed Bicycle Clamp Ring Front Gear Derailleur - China Bicycle Accessories, Bicycle Freewheel | Made-in-China.com