Latest regulations, industry case studies and unbiased articles written by experts
Latest regulations, news and unbiased articles written by experts
The best articles written by experts
The Journal for Employee Protection
  • Latest Issue
  • Trending
  • Press
  • Videos
  • Events
The BLS 4000 Series
Twin filter half mask with bayonet connection

Half mask 4000 series can be disassembled in less than a minute. This way, cleaning is quicker and easier.


Available in soft thermoplastic rubber (4000 R) or silicone rubber (4000 S) for better comfort and perfect fit.

Filters fitting

The bayonet fitting system (b-lock BLS technology) provides a quick and safe filter attachment.


Attached to the rigid body of the half mask by 4 fixing points, does not mark the user’s face. Millimetric adjustment for a simple and comfortable fit.

These are the available versions:

  • BLS 4000 R - Thermoplastic rubber. Size (S/M) (M/L)
  • BLS 4000 S - Silicone rubber. Size (S/M) (M/L)

There are 4 pre mounted ready-to-use kits with these filters:

  • A2 filters + P2 NR prefilters
  • ABEK1P3 R
  • P3 R
  • A2P3 R

Click here for more info

Share this article with your friends
BLS started its activity in Milan by setting up its first production laboratories and offices in 1976. Today, they have spread to Spain, Brazil and the Netherlands, and provide a range of reusable and disposable respiratory protection.