I use one too. I've also heard them referred to as 'limited choke' collars. I've seen them in all nylon, all chain or a combination (which I prefer).
Here's one similar to George's -- http://www.ruffwear.com/s.nl/sc.2/category...it.A/id.1423/.f
Here's one similar to George's -- http://www.ruffwear.com/s.nl/sc.2/category...it.A/id.1423/.f
