It is a compression sleeve designed to provide support for the thigh.
Based on the product packaging and similar items, this type of support is used for:
Compression: It offers multi-directional compression to help with circulation and muscle support.
Pain Relief: It can help relieve stiff and sore muscles, and aid in the recovery of strains and pulls in the groin, hamstring, and quadriceps.
Stability: It provides support to the thigh, which can help prevent re-injury during physical activity.
Comfort: The packaging mentions features like "Flatlock Stitching Technology" and "Durable Reinforced Edging," suggesting it is designed to be comfortable and secure without restricting movement.