RDS OG Puffy Flexfit Hat (Black/Camo) Small/Medium The Original RDS FlexFit Hat is the one that started it all and continues to be our top seller to this day. The Red Dragon Cap is a wool blend with our 3D Puff Chung embroidery. An icon in its own right, Flexfit the One and Only Original cap has elevated the urban, lifestyle, and sports market with its revolutionary all-around stretch-fit technology and polished style.