Back Plate is tem I use for base of my backpack for fursuit (under fur). It will be used for mechanism of wings, batteries, Arduino and water (hydratation) bag.
I am still not sure about placement of water bag (because I do not know if it will fit) but I want it to be my water source (for hydration, possibly 2l) while in Fursuit. Because they have valves controlled by hand (you take off the cover and can drink), I will also need
Bite Valve(like this one) where you open it once (when going into Fursuit) and then only slightly bite it to open it to drink.
I want the Back Plate because of Wings Mechanism (I need to attach it to something).
Plate itself will probably be made of metal.
There is another problem - I want to have a Cooling Vest but because of the Back Plate, I cannot have anything between my back and the Back Plate (to not damage it). That is why I will only need to buy Spare Set of PCM Inserts and make a vest by myself (or use Performers Vest with Insers only on front).