C.R. Snelgrove Co.I have two of these temperature contolled crystal ovens which are designed to operate from a 6-12volt supply. They have standard 8pin octal bases and are manufactured from copper. Toronto Otario, Canada. The firm was taken over and became the Frequency Control Division of Leigh Instruments Ltdin Ottowa.
These are two of several items given to me by Deborah Waters, which belonged to her late father.
Internal view showing the the crystals and the internal cover.