needle gauge from Lykke made from mango wood.
they incorporate a 4" / 10cm yarn gauge along the side and measure needles from 1.75mm to 12mm
hole sizes include
1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 9, 10, 12mm