Models NEMA 14 round. NEMA-14STH20 36mm*20mm stepper motor 28 407 0 In situ 3D bioprinter printing head 0 9 0 TB6612FNG Driver 15 1309 1 Fitec FS90R Micro Servo 22 1481 2 Foldable box 5 26 0 1703 Fan 5 179 0