the p7 torch slides in, lens up which allows the on/off/dim button to be operated from the space at the base. when the top is closed it fits snugly against the lens and the top has a cut out space in which the filter neck is stored, meaning the filter works whilst the torch is holstered. why would you want to do that? well the holster/pouch has a very sturdy swivel clip so i can twist it through 90 degrees and clip it to the shoulder strap of my backpack, allowing the torch, at shoulder height to shine down in front of me with the filter in place if i wish. very well thought out.
or you just remove the filter neck, basically a rubber collar, slightly wider than the lens, which slides over the lens to hold your chosen filter in place.
the pouch has a tight pocket to keep the other coloued lenses and is about the same size as the original pouch which comes with the p7, although it has the swivel mount on the back.
i would use this mounted on my shoulder straps rather than a head torch, meaning i only need one torch, not two.