As the product description clearly states, this is for the Niu40 Preonic, but the key caps for the four rows closest to the typist fit my planck olkb perfectly. Those for the top row are of a higher profile and are so wobbly as to be unusable for me. No matter, there are enough suitable caps to outfit my 40% planck and the price is right. The key caps have a slightly gritty feel to me, which I like. I chose the blank key caps because I have found that legends confuse me, given the amount of custom programming that I have applied to the keyboard.The home row bump keys don't have enough contrast to suit me so this is what I did: Took some fine speaker wire, cut lengths less than the width of the top of the keycaps. Using a Q tip, applied a little clear rustoleum spray finish (accumulated by spraying into a small container) to the top of the keycap, pressed the wire against the paint, let set up for a few minutes, then applied some more over the wires. The result, very tactile bumps. Essential for me, and they don't look too bad. Surprisingly, the application of the spray finish did not smooth over the grittiness which I like.Clear polyurethane works well too.I'm giving this five stars because the price fits the quality. I'm sure better quality is available at a higher price.