I can help you out there Ian. Geronimo's chute is a 16 panel chute which is classed as a sport chute. The 20 panel chute is the same diameter but has more panels for a more scale look. The 24 panel chute grows to a diameter approximately 1.75" larger.

The 16 panel sport and 20 panel scale chute are close to 16" in diameter when inflated.

The 24 panel chute is close to an 18" diameter when inflated.

John