The specifications for the zippers are all based on the UK Ministry of Defence Interim Defence Standard 53-100/1, issued in August 1990.

This Specification recognised only Neoprene coated fabric as the base for the zippers.

This Spec is now "obsolescent" due to Imperial Measurements and financial restrictions on such specifications and their management.

The New Zipper Co, in association with both Royal Navy and Royal Air Force users introduced a higher performance specification in 1998. It is to this higher Internal Specification (BASE5004) that all "BDM" zippers are now manufactured. This includes PVC and PU tape based zippers. The only noticeably variable aspect is the Pressure Tightness which varies from material to material. However all the Test Methods remain the same. The Performance Requirement Values have been raised. The following pages linked to this document contain the Abbreviated Specifications... commonly known as "Short Specs"

Six pitch (Heavy Duty) Neoprene, also known as 12TZ: 06 Pitch Neo

Eight pitch (Medium Duty) Neoprene, also known as 8TZ: 8 Pitch Neo

Eight pitch (Medium Duty) PU: 8 Pitch PU

Eight pitch (Medium Duty) PVC: 8 Pitch PVC

Eight pitch (Medium Duty) PE: 8 Pitch PE

Ten pitch (Light Duty) Neoprene, also known as 4TZ: 10 Pitch Neoprene

Ten pitch (Light Duty) PVC: 10 Pitch PVC now available Black or White

Ten pitch (Light Duty): PU not available at present, but we are working on it...