compatible with all essential oils, each pad can be used for up to 8 weeks, one pack contains 5 pads to order the peri diffuser, please click here.the peri stone diffuser refills are made for use with the super-sleek & ultra-portable peri stone diffuser//p 256//class=f-brand!important. with its waterless fan diffuser technology, the peri stone means that you can soak up the therapeutic properties of aromatherapy on the go. one pack contains 5 diffuser refills, which are compatible with all of our aromatherapy oils//caroma//class=f-brand!important. apply 3-7 drops of your favourite essential oil onto the felt pad inside the cover & enjoy. you can enjoy each pad for up to 8 weeks. want to learn more about the peri stone diffuser refills? drop a line to one of our expert nutrition advisors//aadvice//class=f-brand!important. you can also find out more about essential oils & how to use them here.