Amazon.com: uxcell Gear Motor with Encoder DC 12V 201RPM Gear Ratio 21.3:1 D Shaft Metal Encoder Gear Motor Silver 25Dx49L mm for Robot RC Model DIY Engine : Toys & Games
Pololu - Magnetic Encoder Pair Kit for 20D mm Metal Gearmotors, 20 CPR, 2.7-18V
40gz495h Dc Gear Encoder Motor 12v 8-470rpm With Electric Gearbox Reducer High Torque Electric Turbo Gear Motor With Encoder - Dc Motor - AliExpress
Precision digital encoders for DC and EC motors
Amazon.com: Encoder Motor Set, Dc Gear Motor Shaft DC Gear Motor Small Motor Car Kit Dc Motor Encoder for Printer for Robot(60RPM) : Toys & Games
What Does an Rotary Encoder Do for Electric Motors? - Motion+Drives
Premium N20 Gear Motor (100:1 Ratio, 270 RPM, with Encoder) - ServoCity