(!!!!!) (Best Single) EL34 Mullard UK XF1 NOS 1959 double "O-O" getter halos (83ma) (1st version after metal base) (very rare)
(!!!!) (Best Value XF2 Pair) EL34 Mullard XF2 NOS (1) double halo "O-O" (1) single halo "O" 1966 and 1970 (75ma and 78ma)
(!!!!) (Recommended XF2 Pair) EL34 Mullard XF2 NOS (1 tube) double halo "O-O" (1 tube) single halo "O" 1967-1968 (90.5ma and 92.8ma)
(!!!) (Best Value XF2) EL34 Mullard branded GE XF2 double halo "O-O" 1966 guide pin broke off (102.5ma)
(Good Value Pair) EL34 Mullard UK XF2 single halo used/good 1969-1972 (83.6ma and 85.6ma)
