Originally Posted by TokyoSeven
That would be your handguard/foregrip.
As I said above you will require to inspect your front foregrip/handguard and see if there are any screw holes to mount that rail piece. If not then it is up to you to decide if you wish to drill some.
I do have holes on the bottom part of the handguard but I want to verify with a smart person with airsoft that it will fit. Here is a picture of the holes on my gun: