Hickok 600A Mutual Conductance Tube Tester 
Calibrated & Clean - Ready to Use 
Please see pictures 5, 6, and 7 for the calibration report and other important information. These 3 pages will tell you all you need to know about this 600A, and has equivalent Gm test results as compared the 539C.
 
It comes with a DVD that includes the manuals, foreign and obsolete tube data, Western Electric tube data, and a lot of other information for the 600A.
Please see the calibration information in the pictures.
 
Free Insured Shipping in 48 Contiguous USA
 
Please contact in advance of purchase for shipping costs internationally. 
You can generally determine the shipping costs to your location by using 19X14X12” box weighing 20 pounds shipped from zip code 86332. We ship internationally with FedEx and USPS.