Calling All Tool Nerds! WTF Is This? - #15

I have no idea what this is.

Do you?

It has no moving parts,
and it doesn't come apart.

If you recognize this,
please tell me: 

1.  what it is--please be specific--I don't know about these things!

2.  what it's intended to be used for

3.  if it still looks useable for its original purpose

4.  alternative ideas on how to use it.

I'm so excited to be figuring things out--piece by piece!
And I'm super grateful for your assistance!

Check out my past posts and see if you have ideas about these items too.

WTF Is This? #1  We still don't know what this is!  Can you help?
WTF Is This?  #2  I believe we have a consensus on this one!  See what it is!
WTF Is This? #3  Likely a car part - transmission or drive shaft?
WTF Is This? #4  Nobody seems to have any idea what this is!
WTF Is This? #5   Lots of ideas on this one--a pulley, drill bit, craft rolling pin, torque limiter...
WTF Is This? #6  Perhaps a roller for a sliding door, an adjustable bearing
WTF Is This? #7  Dresser for a grinding wheel
WTF Is This? #8  Flame spreader for a propane torch?
WTF Is This?  #9  Radiator top support bracket with bushing
WTF Is This? #10   No one has given input to this one!
WTF Is This? #11  A consensus!!  Arrow head points for modern hollow metal arrows
WTF Is This? #12  A bracket!!!
WTF Is This?  #13 Grease nipples/Grease fittings
WTF Is This? #14  A night light!

Come back soon for  WTF Is This? - #16