romeviSince Tai Hao is the manufacturer I would personally guess these are costar stabilizers with cruciform (cherry mx) inserts, which is what Matias uses. However, I'd love to see confirmation on that.
AlexPkThis key-set would actually make the Matias Keyboard the logical purchase here because for so long there wasn't anything available to fill out their keyboards but it looks like someone has come to the ALPs party here.
Waiting to hear from you if all the modifiers are able to use this key-set ; )