Shimano RevoShift SL-RS25 Twist Grip Shifter -3/6/18 Speed Black US New | eBay
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
Mountain Bike Revoshift Shift Lever | Shimano Shifters Revoshift - Shimano Sl-rs36 - Aliexpress
Amazon.com: ZUKKA Revoshift 6 Speed Shimano Right Shift Lever SL-RS35-6R Bicycle Twist Shifter Lever Mountain Bike Commuter Bike Folding Bike : Sports & Outdoors
Shimano Tourney Sl-rs35 Mountain Bike Clamp Band 3x7/6-speed Revoshift Shift Lever Iamok Shifter Bicycle Parts - Bicycle Derailleur - AliExpress