Njoy toys are cast in 316 grade stainless steel, and hand-polished to a mirror shine - the 316 material provides superior corrosion resistance, a deliciously deep and lustrous finish, and added strength and toughness.
Njoy sex toys are non-porous, and can be cleaned or sterilized by any means. Stainless steel has low 'specific heat', which means that it's cold to the touch, but it will warm quickly to body temperature. Of course if you're partial to temperature/sensation play, a few minutes in the fridge (Do Not use freezer!) will provide a 'chilling' experience; and likewise a short dip in a bowl of warm water will yield a luxuriously warm and sensual toy for your pleasure.
About the only thing you can do to damage your lovely njoy toys is to use an abrasive to clean them, so please don't.