Old Gap flight cap. I bought it at a used clothing store, but it doesn't fit, so I'm reluctantly selling it. I think it's a rare item, even among Old Gap pieces. Please be aware of the condition as it is y2k vintage clothing. thinsulate… A thin, light, and warm ideal insulation material. 3M™ Thinsulate™ high-performance insulation material was developed to make you more comfortable in cold seasons. It achieves excellent insulation due to its fine fiber structure. It's a technology that makes "warm and not thick" possible. Based on scientific analysis, it is used worldwide in winter sports wear, town casual wear, fashionable wear, gloves, boots, hats, and bedding, providing slim and comfortable warmth.