These 100% natural wool merino felt acoustic dampeners, made in the USA, fit specific Norbauer housings. When installed in the bottom of the housing (resting on the rear cover plate or lower half), it can subtly enhance the luxurious "thockiness" of your build by absorbing internal sound reflections (ping and reverb).
Depending on the option you select, the dampeners support the Norbaforce Mark I and II, the Norbatouch (all rounds), and the Heavy-6.
The dampener has been made with through-holes for clearance of low-hanging electronics components on the PCB of each keyboard that the housing is designed to hold.
This is a pre-order, slated to ship ship in October. I'm ordering a few extras, which will be available for pre-order until they're sold out (likely before the pre-order ships).
The following video shows a sound comparison using the Norbaforce as an example.