Product Description：
This ebay item include:

1 x 3A 57 Stepper Motor NEMA23 with reduction gear 20:1
1 x 80mm 4 Jaw Chuck （diameter 80MM jaw self-centering card dribbling full set of accessories）
1 x Holding Steel frame
1 x Manual tailstock
 
Height: 110mm
diameter 80MM jaw self-centering card dribbling full set of accessories
chuck center height 70MM

The MACH3 set pulse volume Description: rotate 1 degree required number of pulses
Formula: 360 / step angle * driven segments drive*20 / 360 degrees = MACH3 Pulse 
 
Welcome check my other item, thank you!

3-Jaw Chuck diameter 80mm ebay item number 292107587597
3-Jaw Chuck diameter 100mm ebay item number 301628670797
4-Jaw Chuck diameter 80mm ebay item number 292107588850
4-Jaw Chuck diameter 100mm ebay item number 301436375608