Teppan

One of the rare and simple tools from the Ninja's arsenal is Teppan, 
which translated means square plate.
I have not in detail investigating information about this tool, but when I learned more, I'll put all info about them here.

For now, I know it can be used as Shaken (Shuriken), means to throw, used for hitting and blocking blades.
Could be used while climbing (inserting into small cracks or gaps on stone or wood), if you know the proper way, it can be tied to end of the rope, or a belt, and so you get a tool similar Kusarifundo, but I did not say that to you, right : )

but generally, only your imagination limits the use of this tool, ANY TOOL, 

if you are real Budoka remember that.

Below  is few picture of Teppan made ​​of black rubber, for training, normally.

I recently found them in a box in my workshop, 
so if someone like to have it, could contact me by e-mail,  like all other equipment which I usually do, here is also the option of customize, by your needs and dimensions,
Dimensions vary, because of this I make them in two sizes and two thicknesses, you'll be able to see that on pictures.

In this way, everyone can adapt to his needs during training.