My ABZ came with only the small dot position markers on the fretboard, and I knew I would have wanted Speedo bars or something bigger like that so that I could see where I was on the neck. I found the dots just too small for my aging eyes, and they are sort of blocked by the strings anyway. I found these stick on mock inlay blocks on Amazon for about $10, and they are fantastic. They are made of some sort of aluminum foil with an adhesive that is reasonably strong, but totally removable. I am delighted with the results - reminds me of Eddie Murphy at the beginning of the movie Trading Places -- "I can see! I can see!"
I wanted to cut them on an angle to make them look like the factory ones, but that would have made them so narrow as to look very silly because of the steep angle on the lower notes, so I opted to just leave them uncut, figuring if they looked horrible, I could just toss them in the trash and get another set. But they're actually decent like this. I lined up the edge of the sticker exactly with the edge of each dot to cover it. Had to get a little fancy on the octaves (double dots) by cutting the stickers in half. Not winning any awards for aesthetics, but it gets the job done, and will allow me to enjoy this bass a lot more.