You used to be able to select the model you wanted and then click what options you were looking for, sights, mag extensions, grip plugs, etc. Then you could order the gun and it would come with all the goodies installed that you selected. I bought two from them this way, but it doesn't seem you can select all the add-ons anymore.

Not that its hard to install parts in a Glock, but it was nice to take it out of the box all ready to go with what you picked.