hhkb secret sauce
0.5mm plate gasket foam by sho.
it compatible with hhkb classics, hybrid and s60 series.
purchase link (Not advertising):
1. Taobao (China mainland service. maybe you need to proxy services)
【淘宝】https://m.tb.cn/h.gcqdq48vymTIpw4?tk=...
2. Ask him on discord server
/ discord