The 4gb spy pen is one of the most searched, purchased and used of all the spy pens available on the market today. But this begs the question, why? What's so good about this specific set up that's leads to it being so successful.

The spy pen itself will break down into to half's, the lower segment; the pen will be a good standard pen with a smaller ink supply than usual. This is to accommodate for the top section, this part contains all the working camera pieces.

The main bulk of this will consist of two pieces, the 4gb DVR recorder and the battery. These to items are the link that seems to be the success of the pen. The 4gb memory in the DVR will be expected to hold roughly 4-6 hours worth of footage. This is a decent quality but more is always better, so why don't they go bigger?

The battery is the reason; in a typical spy pen you would expect the battery to last approximately 3-4 hours at absolute best. Simply put, there is no reason for the spy pen camera to be able to record any more footage because the pen would die before it can record it.

In terms of making a single recording this makes the 4gb spy pen the ideal tool, most spy camera pens allow you to make multiple recordings within the device also so the extra memory is provided. But most find the period when they recharge the ideal time to download the content and clear its memory. This is why a bigger memory size is currently unneeded and excessive.

To combat this they have adopted a charge as you go system for some of the pens why by holding a AA battery to the pen for 30mins will give you another 3 hours of filming. This will hopefully increase the size and allow us to use our spy pens for a longer period. Until this is perfected ill stick with my 4gb spy recorder pen for now.