Military backpacks (v2) , inspired of the AMA mod

So now in this mod we have 8 backpacks with 2 types, each type have 4 colours, 

As you see

Here the basics backpacks 

Here the large backpack 

You might love the first one or the second one anyway the difference between them is the recipe and the model only 

They have the same number of slots 

And you can wear them and put them in the foot slot 

And they have the same number for the slots

And also they are craft able

Warning

dont ask me to change the number for there slots , because Minecraft only allow 27 slots for the entities, but if i will change it i must make a huge cods , and i can't do that because I don't know how to make that