Why would you need this? The biggest problem with launching bottle rockets is getting air into the rocket at locations that are remote and thus far from an electrical outlet. This requires an air compressor, lots of air line and a storage space. Using a scuba tank allows the teacher to mount it on a dolly and pull it to the launch sight. One scuba tank is good for 400-500 launches and costs only $6.00 to refill. The total cost of the scuba tank system is roughly similar to a quality air compressor system and much, much more convenient.
You provide the scuba tank (from your local dive shop), and Nerds, Inc will provide the scuba tank adaptor kit. The scuba tank system is just the ticket for teachers with Model C, Model D, or Model E launch pads.