ID: 
2280
Maker's Name: 
Westinghouse
Where made: 
USA
Dimensions: 
6.9 × 3.9 × 4.5 cm

This is a small Selenium full-wave rectifier 5 mA rating, mounted on paxolin, on wooden standoffs and four brass terminals. It was used with a DC d'Arsonval meter in lab experiments.