From the manufacturers of the Stihl 2-in-1 filing guide... 

PFERD Chain Saw Sharp CS-X

PFERD offers sharpeners for both manually and mechanically sharpening saw chains. Sharpeners from PFERD stand out because of their durability and ease of use. Chain saw sharpeners from PFERD are ideal for manually sharpening saw chains. Manual sharpening is more economical and gentler than machine-based sharpening, and it prolongs the operating life of the saw chain if re-sharpened at an early stage. The CHAIN SHARP CS-X chain saw sharpener stands out because of its ideal file position, ergonomic shape, and easy handling. The device provides a sharpening angle of 30°.

Advantages:

• Flexible use on site due to compact device design.
• Easy to use due to its defined sharpening angle.
• Long tool life due to interchangeable files.
• Turn the device over to change from the right to the left tooth – no conversion work required.
• Shape is optimized for precise guidance and optimal sharpening results.
• Modern design makes it easy to replace the files.
• Simultaneously sharpen the saw teeth and adjust the depth gauge.
• Precise and uniform sharpening result, even for inexperienced users.

Technical Specifications:

CS-X 7/32" (5.5mm) 

• Chain pitch: .404
• Cut: Classic Line
• EDP no.: 17304
• Length: 12,4
• PFERD type: CS-X
• Suitable for diameter: 7/32

CS-X 5/32" (4.0mm)

• Chain pitch: 3/8 LP
• Cut: Classic Line
• EDP no.: 17300
• Length: 12,4
• PFERD type: CS-X
• Suitable for diameter: 5/32

CS-X 3/16" (4.8mm)

• Chain pitch: .325
• Cut: Classic Line
• EDP no.: 17301
• Length: 12,4
• PFERD type: CS-X
• Suitable for diameter: 3/16 inch

CS-X 13/64" (5.16mm) 

• Chain pitch: 3/8
• Cut: Classic Line
• EDP no.: 17303
• Length: 12,4
• PFERD type: CS-X
• Suitable for diameter: 13/64