I have a Tipro POS keyboard that has relegndable keycaps, but the majority of the keycaps on it are missing the top clear plastic bit that clips onto the keycap. Unfortunately, it seems these tops are not available to purchase. You may be able to get some secondhand from a seller on deskthority.net, but the cost including shipping is likely to be near the cost of the keyboard itself.
The nearest thing I have been able to find available new is a complete key replacement that comes with its own plastic top cover. The transparent top cover is incompatible with the Tipro MID keycaps, so you would need to replace the whole key. The set I purchased from Ali Express was titled 1/10/pcs Transparent Keycaps Double-layer Keycaps Removable Paper Clips Custom MX Switch Relegendable Keycap Shell Protection
. The link for them was: https://www.aliexpress.com/item/1005004623750938.html.
Although these keycaps are pretty cheap, my keyboard has 80 keys that are missing the plastic lid. So it would still cost me about £18 to replace them all, which is a good way towards the full cost of the keyboard. Plus, you have to pull every single key and replace it compared to just clipping on a plastic cover on top of the existing keys. Anyway, I just ordered one pack of white/grey and one pack of black to see what they are like.
Although the height of the unmounted keycap is similar to the Tipro MID, the centre mounting column is much longer. This means the keys sit higher than the original MID keys. The top of the new key without its plastic cover sits at around the same height as a MID key with its plastic cover. So if you just wanted to get all keys to a standard height, then that would work. But as soon as you add the plastic cover on the Ali Express keys, they are higher than the Tipro MIDs with their plastic covers.
Tipro MID keycap (left) vs Cheap AliExpress relegendable keycap (right), both without top lid / cover
Tipro MID keycap (left) vs Cheap AliExpress relegendable keycap (right) underside view
Mounted on the keyboard you can see the Tipro MID keycaps with tops attached are about the same height as the black AliExpress Relegendable keycap without its top attached. The white / grey AliExpress relegendable keycap with the top attached you can see is much taller in profile. Below that you can see the Tipro MID keycaps without their tops.
Top view, you can (just about) see the extra space around the cheap black keycap because it doesn't have its lid attached.The style of the keys is also slightly different. The Tipros have more of a slant at the front and are pretty straight up at the back. Whereas the new keys have a very slight slant that is the same on all 4 sides.
I would say if you had a Tipro MID keyboard where you wanted to replace all the keys, then these keycaps would be fine. But if you wanted a mix of Tipro MIDs and other keys, then these wouldn't really be suitable due to the height difference. Yes, they are the same height without the transparent tops, but then you're going to have to stick labels on them and the keys are a bit smaller in width and length without the lids clipped on.
