Anyone know what this is?

[procel]

Anyone know what this is called or where to buy one?

(It's for helping to clamp the rear wheel in place when using horizontal drop-outs).

 

[Fab Foodie]

It's called a chain tug .... Google 'em!

 

[Rickshaw Phil]

Chain tug - available from here

 

[cyberknight]

calling @Fnaar

 

[vorsprung]

It's rust and it's widely available

 

[procel]

Thanks all! Found it using google now.

 

[Archie_tect]

Previously known as a bulkhead drain secure wing-nut [last used by Harland and Wolff in 1912].
... where exactly did you 'acquire' it...

 

[Cubist]

Picture not loading.... is it a baby robin?