Welcome to the catalogue.
All of these bobbles come in 3 different lengths (yardages) and 2 different weights. The recommended needle size is 3.25-4mm (US 3-6) for the 4 strand bobbles and 2.75mm-3.5mm (US 2-4) for the 3 strand bobbles. The yarn weight is equivalent to fingering. All the info on bobbles is here. Need inspiration? Your free Mixology Shawl pattern is here