This item actually works very low tech but very practical.
melthEasy to prep just slide in the gel packs and put in freezer for a few hours.
I washed the cap before I put in fridge and used.
I have really bad migraines so I was really invested in this product working for me and it really helped.
I just wish I could buy extra gel packs separately so I could put in fridge and have ready when the inserts melt and need to be put back in freezer for contiuous relief.