Yet another calibration thing

Getting tired of having to redrill/sand the standard holes and fittings I use in my makes, so bit the bullet and made this little calibration block. The block has holes from 2.0 to 2.9 mm in 0.1 mm steps, and likewise for 4.0 to 4.9. I've included a 4 mm (nominal) dowel to check what the printer actually does? The nominal dimensions of the block are indicated. I hope this is useful.