All the parts of the pmag except for the spring. At top left is the dust cover which each pmag comes with. This fits on top of the magazine body, and serves to keep dust and moisture out of the magazine. Immediately below it is the follower, which has both a curved section to trap the top of the magazine spring and a hole to thread the spring through. Also visible is a transparent strip of plastic on the pmag body (bottom part), which is the window the magazines were named after. Notice that the magazine does not go all the way to the top, as a significant part of the magazine is inside of the rifle when in use.
The two halves of the floorplate assembly nested together. Note that they appear to be made of two different plastics. Also note the protrusion on the top piece. This is contoured so that it traps the magazine spring.
A view down the top of a Pmag. Note the curvature - this is why so few of the parts from other magazines will interchange with it. Also note that there's a few rough patches where the plastic wasn't fully deburred (right side, inside), but this is strictly a cosmetic issue and should not impede function.
Clipping the dust cover over the top of the magazine. Note that the front of the dust cover hooks into a groove in the front of the mag, and then hinges on towards the rear.
The dust cover, installed. As you can see, it's a very solid fit and should keep just about any dust out of the magazine.
-- SeanNewton - 09 Jun 2011