[NovaKaynE]

If you get the full stock version, I think the mechbox will be wired to the back. So you can store the battery inside the stock. If you get the collapsing stock, it will most likely be wired to the front. Which means you will have to store the battery in the fore grip/hand guard. Know this, if the gun is wired to the front, you can still mod it with a full stock. But you won't be able to store the battery in the stock, it will have to be stored in the fore grip. The only problem with this method is your battery size is limited to how big your fore grip is. Whereas a full stock will accommodate any battery you choose.

You can also buy a fore grip with the built in flashlight. So with the quick pop of two pins, you can turn your MP5 from a full size MP5 into a more compact weapon.

The MP5 SD5 is the full size MP5 with a silencer and the MP5 SD6 is the MP5 with a collapsing stock and silencer. Just type all the gun descriptions in google images and you'll see.