Amazon.com: BESNIN Shifter and Brake Combo Bike Shifter&Brake 1 Pair 3x7 21Speed Mountain Bike shifters Shifter and Left/Right Brake Lever Set for Mountain Bike Folding Bike Universal (3x7 21speed) : Sports &
Amazon.com: FOMTOR 3x7 Bike Shifters Set 21Speed Mountain Bike Shifters Left Right Brake Lever Shifter with Shift Cables for Mountain Bike Folding Bike,V-Brake (1 Pair) : Sports & Outdoors