This version is the Coke Bottle style, considered by many as the best sounding Shuguang 6L6s. Brand new vacuum tubes made for OEM by Shuguang to exacting specs and tolerances. They were to be used in new amp production and are not labeled or packaged to be on a sales shelf. Beam power tube/valve numbers 6L6GC, 6L6GCR, 6L6G, 6L6GA, 6L6GB. These tubes are compatible with 5881 and any 6L6 . 

Tested on a RoeTest professional computer testing system, the best tester available today. Matched using a Maxi Matcher 2.

You get 4 matched tubes.