The Neo Ring comes with a magnetic cover. Since the unit is very delicate, it is recommended that it be worn with protection during normal use. The material used is called aluminum honeycomb. It is a delicate material consisting of very thin sheets laminated together, so please handle it with care. If force is applied to it, it will remain stretched and will not return to its original shape. There is a magnetic cover, so please enjoy it while wearing the cover. Although it is metal, it is a mysterious new ring that moves smoothly.