... the ear tips on all Littman stethoscopesFood grade material of stethoscope ear plugs: FDA or SGS certificate Oxidation , Chemical, ... , weather resistance colorful ,Anti-aging,good flexibility, good elasticityItem:Stethoscope Ear Plugs Material:NBR,HNBR,XNBR,EPDM,SIL,FKM(VITON ... needs.Sample:Free After-Sales Service: 100% responsible for stethoscope ear plugs, supply active feedback within 24 hours and ...