Good to know- These hot & cold rings are designed to be used with the Theraface Pro Face Massager (sold separately)- They cool and heat quickly thanks to Cryothermal Technology - you can pick from 3 temperature options for each ring- The hot ring can be used to increase blood flow and reduce tension and pain- The cold ring is ideal for helping reduce puffiness under eyes, pain, inflammation, and muscle spasms- Both rings help your skin to better absorb creams and improve radiance- You can also combine the cold ring with the TheraFace Massager's percussive attachment (sold separately) and create a customised routine________________________________Please note: It is recommended not to use the Hot Ring if you have melasma or hyperpigmentation, especially if it is exacerbated by mild warmth.