![](https://coimages.sciencemuseumgroup.org.uk/50/675/large_thumbnail_1972_0141_0248__0002_.jpg)
McVitie Weston valve collection
- Made:
- 1927 in United States and Canada
- maker:
- Mullard Limited
![Mullard valve, type PM5B, marked A277](https://coimages.sciencemuseumgroup.org.uk/453/330/medium_smg00262717.jpg)
Mullard valve, type PM5B, marked A277, (RMW/D51 - McVitie Weston number), by Mullard Limited, 1927.
Mullard valve, type PM5B, marked A277, (RMW/D51 - McVitie Weston number), by Mullard Limited, 1927.