Potomac Field Gear FROG (Flame Resistant Organizational Gear) long sleeve mock neck shirts in sand/tan heather. Made in the USA, these tactical base layers feature a high-performance modacrylic blend with X-Static for antimicrobial and flame-resistant protection. The lightweight, stretchy fabric and flatlock seams provide comfort under armor or as a standalone top. Ideal for tactical training, outdoor work, or cold-weather layering.