ID: 
2289
Maker's Name: 
IT&T
Where made: 
USA
Dimensions: 
18.5 × 1.4 × 1.4 cm

The glass tube contains approximately 150 discs with plated brass end-caps, designed to be mounted in a tool clip holder.

It is a half-wave rectifier, of unknown voltage rating, but low current, with positive polarity marked with red paint at one end.