A cover for your light bulbs to keep them from exploding when dropped... Not that this has ever happened to me before :) I've also included just the socket nut so you can make sure it will fit your socket without having to print the entire cover. For reference though, this is the kind of socket I'm using: http://www.lowes.com/pd_75178-37672-884443_4294722560__?productId=3379446&Ns=p_product_avg_rating|1&pl=1¤tURL=%3FNs%3Dp_product_avg_rating%7C1&facetInfo= Also, this makes use of syvwlch's fantastic thread library at http://www.thingiverse.com/thing:8793 I've been able to print this with PLA pretty successfully. The holes in the cover help disperse the heat but it would definitely work better if printed in ABS. Enjoy!Print (I'd recommend using a 3mm brim or so to make sure it stays stuck to your printbed) Screw cover onto socket