5GU-15-K stepper motor 
Gearhead Specifications

• Type: Parallel Shaft GU-K Gearhead
• Reduction Ratio: 15:1 (labeled as 15K)
• Frame Size: 90 mm x 90 mm (Size code 5)
• Compatible Motor Types: Standard AC induction, reversible, or electromagnetic brake motors (e.g., Oriental Motor 5GU series compatibility) 

Key Functions

• Converts high motor RPM into lower speed and much higher torque.
• Flange-mounts directly onto matching 90mm round or pinion-shaft AC gear motors. 

If you meant a different part number or need help finding a compatible AC motor or a true stepper motor with similar specifications, please let me know your application requirements (such as required torque or voltage).