This Styrofoam shipping cooler will hold up to 4 packs of liquid yeast and 4 total ice packs.
This container will help keep the heat away but will not keep your yeast cool in every case. It helps to keep your yeast from getting so hot that viability is significantly degraded. Don't expect yeast to arrive cold from May-November, and max out the ice packs. Dry yeast is always a great option for the hotter months.
Starters are strongly recommended for all shipped liquid yeast regardless of shipping method, transit time, or cooling protection.