In Goldeneye (1995) Q-Branch supplies Bond with a Parker Jotter pen that is a C4 grenade: three clicks arms the four-second fuse, another three disarms it. A classic pen, still widely available.
Maybe the most useful and affordable James Bond gadget around! The Jotter has a stainless steel cap, barrel and button with chrome coloured trim. At the time of the movie, a special edition of this Parker Jotter was available in a unique 007 gift box, see the photo on the left.
In SkyFall (2012) other Parker pens are used by M.