interesting way to self care [SEP] this roller is made out of lightweight plastic base and a a little sturdier roll that seems to be filled with some kind of gel the roll is removable and needs to be put in the freezer for about minutes then it is easily inserted back it feels great on my face in the morning wakes me right up and sort of revitalizes plus i use it on my neck to close the pores it works great with localized pain when you need something cold to bring immediate relief i must say it hold cold for a while so one session will last however long you need good roller for pain relief and natural cosmetic treatments