Selling Company is impossible to deal with!!!
I received the APC RBC11 and tried to plug it in to the battery backup, I noticed the plugs weren't connecting correctly. I called my company's IT company and they came out to see why it wasn't fitting. I guess I needed to order RBC55 instead of RBC11. I tried to return it to this company to no avail; I even offered to pay the shipping and a restocking fee, but they wouldn't take the return. I wouldn't recommend this company to anyone BASED ON their customer service, or lack there of.
APC RBC11 Replacement Battery Cartridge 2-pack review by herdafer can be read at Amazon.Com