Catalyst Cryohelmet replacement cold packs Available in 3, 7, 10 and 11 cell units (10 cell sleeves only used in XL size) Each CryoHelmet comes complete with all necessary cold packs.  Additional cold packs sold for those who want to swap in fresh cold packs for longer cooling sessions. Small Cryohelmet uses three 3 Cell, two 7 Cell, and one 11 Cell sleeves. Medium/Large Cryohelmet uses five 3 Cell, two 7 Cell, and one 11 Cell sleeves. Extra Large Cryohelmet uses six 3 Cell, two 10 Cell, and one 11 Cell sleeves.