Current Tele Vue Plossl are 55 (2"), 40, 32, 25, 20, 15, 11, 8
Older models include 26, 21, 17, 13, 10.5, 10.4, 7.4
See
https://www.televue.com/engine/TV3b_...=13&Tab=_chron
10.5mm is not listed in the Chronology. Perhaps was sold when 10.4 was no longer made.