Internal mount for a replacement speaker. After installing the Sotabeams filter module, the stock speaker will no longer fit. The stock speaker is too deep and intersects with the filter board. I found a replacement speaker on Amazon that is shallow enough to fit. The speaker is made by uxcell and is 50mm in diameter and just 8mm thick. This spacer allows you to hot glue the speaker to the spacer, and use the original screws to hold it in place on the top cover of the radio. I'll admit the audio quality of the replacement speaker is not as good as the original. I printed using PETG, 0.2mm thickness.

Amazon speaker link:

https://a.co/d/iGkwXeV

Sotabeams filter module link:

https://www.sotabeams.co.uk/ft-817-filter-module-ssb-cw/