What is this DSLR Battery grip product called?

I recently saw a product designed for DSLR

If you have a battery grip, the original battery fits inside it. It has a tray wherein you can put either an original battery or 6 AA battery

But this product removes the tray altogether and is one big battery. The whole cavity inside is replaced by one big battery.itis also designed to be charged directly with an ac charger. So i theory, you can directly plug your camera to an ac outlet

I saw that it is available for NIkon d3100 and d7000

I forgot the product name

My question is what do you call it and where can i buy it?

Your first thought was right, it's called a Battery Grip. If you can order online in the Philippines, try Amazon or any of the photography stores such as B&H or Adorama.
http://www.amazon.com/...zon.com/s/

Nikon MB-D11 Multi Power Battery Pack
http://www.bhphotovideo.com/...ttery.html

The battery pack is supplied with two battery trays--one that holds an EN-EL15 rechargeable battery, and one that holds 6 AA batteries

Yes, it is called a "Battery Grip"!

You can get a Nikon battery grip MB-D11 for the D7000. Unfortunately, you can't get a Nikon grip for the D3100 as it is an entry level camera. You will have to find an aftermarket grip from Neewer, Zekios, Polaroid, Meike, etc.