Attenuation ratings are given on the product page...just scroll down...
"Work never sounded so good with the PeltorTM WS Workstyle. Stay protected whilst taking calls wirelessly or streaming music. Wireless Bluetooth® connection to your mobile phone allows you to manage phone calls directly in the headset. Built-in level-dependent function lets wearers hear ambient sound, such as conversation, machine sounds and warning signals Integrated noise cancelling microphone VOX function for handsfree operation of the communication radio Auto power off function Auto power off function Specifications: Attenuation rating (HML) H=32 M=29 L=22 Attenuation rating (SNR) 31 Decibel Battery Life 150 Hours Colour Black Communication Type Wireless Bluetooth®, Two-Way, External Audio Input Connection Type Wireless Bluetooth® Features Advanced VOX (Voice Operated Transmit), DSP (Digital Noise Reduction), PTT Function, Supports Bluetooth A2DP profile for streaming high quality stereo sound Function Bluetooth Hearing Protection Style Headband Net Weight 368 g Product Series WS Series Product Type Communications Headsets Standards/Approvals CE Approved Typical Application High Noise Environment User Type Motorsport, Military & Police, Industry"
Those look really really expensive though....