This is a Harlie Tone Selector and scratch filter from the early 1930's.
Manufactured by Harlie Bros Ltd they were intended to allow you to vary the tone from your radio or gramophone and to remove scratch sounds when gramophone records were played.
It has 5 settings, from 'normal', through 'bright' to 'deep'. According to the publicity material at the time they "definitely improves reproduction from every type of set and loudspeaker".
Made of a brown bakelite it has the Harlie brand name. It is maximum 7cm long and 5.5cm wide.
There are 2 pairs of plugs for the wires between the radio and the speaker.
Overall it is in good condition with no evident damage. I have not tested it and so I do not know whether it works.
Please note. I do my best to accurately photograph and describe the condition of the items for sale, including any minor defects but all pieces are vintage and have had previous lives and so may have minor flaws.
Postage is for UK only, please enquire for overseas postage.