Matias/ALPS compatible keycap with a spherical top profile.
This deep-dished 1.5S size keycap is suitable for the home row of your keyboard. At 2 times the single key width, this key is best for modifier keys.
Based on the DSA family from Signature Plastics but 3D printed with a 1Z mount (but the mount is flush with the bottom of the keycap to make it more suitable for 3D printing.
The center mount is connected to the edges by 4 posts that support the post so it is fully supported during printing. These posts have a small notch at each end, so they can be quickly and accurately clipped off using side cutters before fitting.