Tablet Instrument; Tyers patent permissive slide release plunger; metal cased instrument on wooden stand Tyers patent permissive slide release tablet instrument
Train tablet instrument,Tyers No 6 type, wooden and metal case, painted green. Tyers No 6 Tablet Instrument
No.5 absolute and permissive tablet instrument, pattern B2075, by Tyer & Company. No.5 absolute and permissive tablet instrument
Tyers no.1 train tablet instrument, with galvanometer gong and four tablets. Tyers no 1 tablet instrument
