360°Cooling Breathable Helmet Liner:High quality breathable mesh design summer cycling cap;Lightweight and quick drying,soft, comfortable,elastic,smooth,will not rub or irritate skin, bring you a cool and comfortable head experience in hot summer Fits Under Helmet:Our helmet hard hat liner seamless joining process,only 18 g(about 3 sheets of A4 paper),light and breathable,eliminate the traditional sports cap indentation trouble,wearing long time will not have pressure marks,more comfortable,say goodbye to the smell,the sweat and the itchy feeling Quick Dry Sweat Absorbent Skull Caps:Lightweight polyester mesh hole fibre,fibre cross-section accelerates the diffusion of water,water absorption rate