Expand your valve tester to include 300B
The Orange Valve tester MKII Expansion Module E plugs into your existing Orange Valve tester MKII (purchased separately), enabling it to test the iconic 300B valves. As a plug-in device, it can be easily removed for when you need to test other valve types.
Keep your 300B valve powered devices in tip-top order, with the Orange Valve Tester MKII Expansion Module E.