Amazon.com : Hycline Shimano Bike Rear Derailleur RD-TY21B 6/7 Speed Direct Mount for Mountain Bicycle-Black : Sports & Outdoors
Amazon.com : ZUKKA Shimano Rear Derailleur RD-TY200 6/7 Speed Direct Mount for MTB Mountain Bicycles : Sports & Outdoors
Shimano Tourney RD-TY300-SGS Rear Derailleur - 6/7 Speed, Long Cage – The Path Bike Shop
New 7 speed commuter with Shimano SIS index. No noise on stand, shifts smoothly but low clanking sound on road when pedaling in 4th & 5th though not other gears : r/bikewrench