Portwest® Detectable TPR Corded Ear Plugs (50 pairs), Blue, Size (EP07BLU) BOXDetectable and reusable ear plugs in TPR (thermo plastic rubber) material. The detectable feature is manufactured with an advanced technique by adding metal shaving into the TPR material during the injection process, without the need to add the metal detectable ball. Recommended for use in food industry environments. Each pair comes inside a hygienic polybag with fitting instructions.