so handy to have [SEP] the small bottles that come with the sleeves are easily removed to be filled they are simple to fill from a larger bottle that has a pump for other types of bottles you can use a funnel the bottles don t leak as long as they are securely closed after use the inner bottle is protected from breakage by the sleeve i like that there are options for the colors of sleeveseach bottle has a small carabiner clip that can be used to attach it to a bag or belt loop