This racket’s a bit old but you can still get it.
Buy (UK): pdhsports.com
So apparently Dunlop has now dropped Ramy Ashour and Amr Shabana from their sponsorship list? Hmm. Amr Shabana is not amused:
Anyway here’s Ramy using the Airstick:
Screenshot via PSA Squash TV
And here’s a clip showing what you can do with the Airstick: