Pr of the excellent sounding vintage Sylvania 6L6GA, Coke Bottle,  Power tubes, black plates, 1950s. One tube has gray lettering and the other has green lettering. The tube plates, sizes, configuration are the same.  They both test over 880 on my B&K Mutual Conductance tube tester, where 640 is minimum good. These are known for their excellent sound and performance. Buy with confidence, see my feedback. Good listening, SonnY :)   The shipping cost includes safe packing, insurance, and prompt shipping with tracking number.