haha I asked the same question man when I got my first antec 1040 file server... I had forgotten what they were for I was not really a pc guy but had seen them back in the day. My buddy was like remeber what an isa slot card is..?? I about died that my new hightech case had holders for them. Even my latest aluminum xpider case has them, actually all antec style cases have them tha I know of.