3 Pieces Used Ken Rad VT-231 JAN-CKR-6SN7GT. Black coated glass interior.

All 3 tubes tested on a calibrated TV7D/U Tube Tester and results are as follows :

96-96/50
90-98/50
86-88/50

All 3 Tubes Guarantee Good. No Gas. No Shorts.

Thank You and Good Luck : ) : )