Thickness: The base tan foam liner is about 1/2 inch thick, and the top black liner is about 3/8 inch. Compatibility: Designed to fit inside ACH, MICH, Team Wendy, FMA, and EXF helmets, providing all-day wearability with a comfortable and adjustable fit. Customizable: The protective mat includes two liners that work together as a base and top layer. The tan base and black top are separate and customizable, allowing you to place pads where they best suit your helmet and head shape. Contents: 33 pieces per set. Includes 9 protective mats and 24 hook-and-loop circles for replacements after sweaty days. Use scenarios: - Airsoft or paintball sessions requiring secure, comfortable padding inside compatible helmets. - Extended training or hot conditions where easy replacement and reconfiguration maintain comfort. - Shared or multi-user helmets, enabling quick customization for different head sizes or preferences.