It is a type of material that stretches and is used especially for making clothes fit tightly.
Tee Jays TJ9510 - Lightweight performance softshell Men
BUILD YOUR BRAND BY099 - Women's leggings
FLEXFIT 6277PS - 6-panel cap
FLEXFIT 6277OC - Organic cotton cap
FLEXFIT FX110T - Trucker cap
KORNTEX KX904 - Multifunctional Balaclava hood
FLEXFIT FX5003 - Cotton bob
FLEXFIT 6089CA - Carbon snapback cap