Our these massage cupping cup are made of soft safe BPA free silicone material. It can withstand a high temperature of 250°C. With these cupping cup only several minutes of cupping will be equivalent to half hour of a deep tissue massage. Size and Applications: L (Large) Cup: 70x80mm(Diameter*Height) (Most effective on broad areas such as back or thighs) M (Medium) Cup: 55x55mm(Diameter*Height) (Most Effective for all around limbs or medium sized areas) S (Small) Cup: 37x80mm(Diameter*Height) (For face massage and deep cleansing when used with cleanser) XS (Extra Small) Cup: 15x50mm(Diameter*Height) (For precise applications to small areas of body such as around eyes) 4 sizes, smallest to largest (XS (extra small), S (Small), M (Medium), L (Large), for massage to any parts of body. (If you need only one size of cups then that also you can choose from the size option according to the requirement.) If you need general instructions pdf booklet for these cuppings, please message to us (to seller).