Need help with dog accessories

I was at a dog show recently and notived a van had some kind of lock or bolt that allowed the doors to remain ajar but were still securely locked. this was to allow air to circulate for the dogs inside.
can anyone tell me what the name of this thing is or where i can buy one?
I have trawled the internet for days now but no luck
really appreciate any help you can give me
thanks

It's called a Ventlock and I bought mine years ago at a show. There is a website www.ventlock.com. I've used mine on a car and now on a van and find it very useful.

aw thank you sooooo much you are a life saver....and a time saver, you have no idea how long i trawled the web last nite

Glad to help!