Acer Aspire optical drive form factor question

Hey guys got a question and figured here would be the best place to ask. Anyways getting to the point I've got a couple year old Acer Aspire 5050 series laptop and I've already upgraded it with 4GB of RAM I'm thinking next 2 upgrades are a 500GB HD and a Blu Ray drive as well for both it will only cost about 300 with taxes in in Canada seems better than buying a whole new machine and paying minimum to get those 2 upgrades 2000+ granted I get a bigger screen and a gaming graphics card but with having my XBox 360 and games for it being cheap and plentiful I don't game much on my laptop. so my question is what form factor does the optical drive in my laptop use? Reason I ask is I found an Sony NEC BC-5500A drive on Ebay (HP Branded) it does Blu Ray and of course dual layer DVD burning and I figure more cost effective to simply upgrade since it's only $100 for the unit I found (other units still aren't too bad at $150 with free shipping)

Just want to know if this drive will fit in my laptop.

Thanks in advance,

overlockingrocks