Avo Valve Tester

[pwdrive]

According to someone who's relative worked for AVO at that time, Avo were having problems with the design of the thumbwheel switch but they were under pressure to release a tester so it was released without the switch, this would tie up with the fact that the thumbwheel switch version was released within a year or two of the non switched version according to some old adverts I found on the web.

Lawrence.