Product descriptions consistently list the textile as 100% polyester.
They use a battery-operated fan or pump that runs on 4 AA batteries (most listings specify 4 AA alkaline and state batteries are not included); one listing also references a battery pack being included.
They inflate via a built-in pump or a battery-powered fan; you install the required AA batteries, switch on the fan/pump, and allow the costume to fully expand before securing any closures per the product instructions.
Common details include a cheerful snowman face, a black top hat (occasionally with a decorative flower), festive scarves (green/red), and optional props such as a corncob pipe.
Product details typically specify 4 AA batteries to power the inflation fan or pump.