The Powercap Lite incorporates lithium ion batteries derived straight from the latest mobile telephone battery technology. This has enabled the battery to be incorporated within the headpiece, so it is completely self-contained without any ancillary battery pack. It provides the wearer with a greater feeling of freedom & ease of use, & will provide a consistent airflow of 160 litres a minute for 8 hours continuously, with only 440g head weight. Conforms to EN12941 TH1P.