One piece plastic moulding.
Nothing to connect to back.
I had thought it would have a socket to take a wrench , but that would be TOO much torque. Finger tight ONLY!

The tool is made of plastic. You turn the tool's knurled ring with your fingers. No other tools are required. The axle 'cap' is easily removed uisng this tool.

Its made of hard plastic and is designed to insert into the centre holder bolt on your bottom bracket on a Hollow tech.

Nothing connects to the back of it as you should be able to turn it with your fingers

It is made of plastic and nothing connects to the back of it because very little torque is needed to adjust crank/bearing, just finger-tight.

nylon plastic you use your hand to grip it

Not sure of the precise technical name for the material but it feels like hard plastic.

Its hard plastic and you don't really need to connect anything to it - just turn it like the knob on the telly, when they still had knobs!

The tool is plastic. Nothing connects to the back of it as the cap that it removes should only be installed hand-tight. There are grip ridges at on the edge of the tool. It works fine for screwing in the cap on by hand, but you may need to use some mole-grips on the tool to help turn it when removing the cap, as the cap may get bound on a bit in use.

Nothing connects to it, you hand tighten

A type of plastic.
It is intended to be primarily used by gripping the outer ribbed edge by hand only.
It may have a 1/4" or 3/8" 'insquare' recess in the back of it for use with a low value torque tool.