Amazon.com: 3D Printing Closed Loop Stepper Motor NEMA17 MKS SERVO42 Developed by Makerbase That Prevents Losing Steps from 42 Stepping Motor (with Display) : Industrial & Scientific
Nema 17 Closed Loop Stepper Motor 16Ncm/22.7oz.in with Magnetic Encoder 1000PPR(4000CPR) - 17HS08-1004-ME1K STEPPERONLINE