Soft , SI-Tack's ear plugs that conform to the unique shape of each for excellent hearing protection and comfort. Main feature:Soft disposable polyurethane foam ear plugs providing extra comfort. The tapered shape is designed to adjust to most ear canals. Thet are made from soft hypoallegenic materials. -Approval : The SI-Tack ear plug have been shown to meet safety requirement under Industrial Safety Corp in Korea and EN352,CE and also have NRR30 ANSI S3.19-1974 to the National Standards Institute Specifications. -Material : Disposable ear plug : Polyurethane Reusable ear plug : Polyurethane, Silicone elastomer -Price : Disposable ear plug PU foam : US$0.085/pair with pack (Packing: paper pack, Poly bag) Reuseable ear plug PU foam corded : US$ 0.12/Pair with pack(Packing:paper pack, Poly bag) Cord : PVC, TPU, Polyester string.(The standard is PVC string) Reuseable ear plug silicone elastomer : US$0.25/pair with pack(Packing : paper pack,Poly bag) Cord : polyester string. Best regards, Young Sig Jun