Spider Bungee Adjusters make fitting chains to your tires a fast and easy process. They're constructed of soft pliable rubber that's resistant to cold temperatures and are a snap to install – even with gloves on. 

I am unsure but I believe these are 0218 Spider Truck Bungee Tire Chain Adjuster.  I am told that this pulls the chain evenly, is made of heavy duty rubber and it increases life of chain up to 40 per cent.

They are being sold together.