This new-old-stock testing Matched Pair Sylvania JAN-CHS-6SN7GT / VT-231 Milspec World War II Tubes was tested on my recently-calibrated Hickok 800 for shorts, gas and transconductance.  There were no shorts or gas. 

Tube One:  Transconductance measured 2650/2800 (US Navy logo 4C batch code)
Tube Two:   2600/2600  micromhos (SC966A contract code)

Minimum is 1690; new is within half a standard deviation of 2600.

I also listened to them in my Audio Electronic Supply AE3 preamp and they sounded excellent 
with no noise, hiss or other artifacts. 

Best 6SN7 ever made with terrific flashing, foil getters and solid bases.

US Shipping is USPS First Class Mail with tracking; Priority Mail is also an option if you wish your tubes delivered sooner.

International sales shipping via United States Postal Service (USPS) First Class Mail/Package International depending on 
destination.  International tracking and insurance can only be offered if you purchase USPS Priority Mail 
International for shipment.

Package weighs ten (10) ounces.

Combined shipping always welcome.