Code 3 C3100 siren speaker 90 degree bracket

To the best of our knowledge these are code 3 oem. Due to no markings or model numbers they may be aftermarket. We have checked the holes and the code 3 C3100 speaker fits perfectly. This appears to just be a standard 90 degree L bracket and we are unsure if there is any designed vehicles these were supposed to fit. Just mount to a flat surface and should be good to go. 
Multiple in stock. They all have light scratches, scuffs, grime etc from use. Most appear to have never been used.