Kuroda SG4620B-640H-D0CC-NZ Ball Screw Linear Actuator. 640mm guide rail, 20mm lead. Repeated positioning accuracy +/-3µm. Motor mount is listed as D0, motor face measures ~63mm with ~50mm bolt square distance. 

Configured with two long blocks, one is floating. Maximum stroke is about 15.5" inches with blocks together. Three photoelectric sensors are included, wired together with a Molex-style connector. 

This may need an adapter plate depending on your application, previously used with a Vexta stepper (not included). 

Item weight is 28.1 lbs. Overall length is ~29".