Riverstone Audio One Pair (2 Tubes) 6E2 Magic Eye Vacuum Tubes Fully-Tested, similar to 6HU6/EM87 One Pair (2 tubes) 6E2 Magic Eye Vacuum Tubes. Replacement for 6E2, 6HU6 and EM87 vacuum tubes. Used in vacuum tube audio equipment, VU level indicators. Each tube is circuit checked at 250 VDC for proper operation.