Puncture-Resistant Device 3 : The reinforcement to the bottom of protective footwear that is located between the sole with heel and the insole that is designed to provide puncture resistance
NFPA 1971 Standard on Protective Ensemble for Structural Fire Fighting, 2000 ed. https://www.nfpa.org/Assets/files/AboutTheCodes/19 71/1971-A2006-ROC-Preprint.pdf, (Std: Prot Ens for Stru Fr Fight - Amer) {428 NFC}