This is the 13202nd most frequent German word.
aufblasbaren
Inflatable.
In this sentence, "aufblasbaren" is used as an adjective describing the noun "Ballon", indicating that the balloon can be inflated.
Ich brachte den aufblasbaren Ballon zur Geburtstagsfeier mit.
I brought the inflatable balloon to the birthday party.
Here, "aufblasbaren" is again an adjective, modifying "Schwimmring" to indicate its inflatable property.
Die Kinder spielten mit einem aufblasbaren Schwimmring im Pool.
The children played with an inflatable swim ring in the pool.
In this case, "aufblasbaren" describes "Matratzen", specifying their nature as inflatable.