Found at Blakemere. Two packs for £5.
"THIS IS A SAMPLE PIECE OF TAUT RUSTLESS EXPANDING CURTAIN ROD
BRITISH MADE NICKEL PLATED
SPRING EXPANDING CURTAIN RODS
SPECIALLY DESIGNED FOR USE WITH HOOKWELL PLEATING TAPE."
I remember having this wire on my bedroom window as a child...The sample piece of wire attached is a stroke of genius.
Only four and a half old pence...change from a sixpence.