Models NEMA 14 round. NEMA-14STH20 36mm*20mm stepper motor 29 415 0 In situ 3D bioprinter printing head 0 9 0 TB6612FNG Driver 16 1319 1 Fitec FS90R Micro Servo 23 1491 2 Foldable box 5 26 0 1703 Fan 5 180 0