What is this? *urgent need* HELP!

hi everyone...i need some desperate help on this. i have just ordered the Logitech Z 2300 speakers to go along side with my dell 5.1 speakers and i think ill be needing another one of these things(look below) to attach the additional 3 3.5mm headphone jacks into the pc...( look below ) okay i think im just speaking crap here...im confused.

check the pictures and if anyone knows how many jacks the Logitech Z 2300 uses to connect to the pc - LET ME KNOW! Many thanks

fahim

..whats this thing called? - i tried google millions of times...no luck!




C and C2 is the thing i would like to purchase.
A is the 3 3.5mm jacks that comes from my dell 5.1 speakers that goes into B
D shows A + B connected together and at the end is just 1 3.5mm jack which goes into my pc. ( dell 8400 )

Question once again: what is it called? where can i buy it from ? does the Logitech Z 2300 work in the same way. if it does i plan to buy this additional connector THING and then buy a ' Stereo splitter 3.5mm jack to 2 x 3.5mm sockets ' to connect both of my adaptor things into..

okay okay i know NONE of this THINGY THINGY shit is understandable..im sorry! but any suggestions will be greatly appreciated! thanks once again fahim.