This is a knee support from ZAMST. Used a few times. Washed. Instant purchase is welcome. Product Overview: ・Manufacturer: ZAMST ・Product Name: EK-5 (Knee Support, for Left and Right Knees) ・Size: L size ・Care: Machine washable Size Guide / Thigh Circumference: S / 36-40cm M / 40-44cm L / 44-48cm LL / 48-52cm 3L / 52-56cm Comparison with other ZAMST products: EK-1: For those who want to easily protect their knees EK-3: For those who want to easily reduce instability EK-5: For those who want to easily protect their knees during exercise EK-MOTION: For those who want to prioritize both fixation and ease of movement EK-PROTECT: For those who want to firmly fix their knees I used this in the past when I had knee pain due to iliotibial band syndrome, but I only used it a few times because I stopped running. Please see the official website for more details.