- Size: 41 • High-quality viscoelastic foam 8 mm to 10 mm thick, originally used in the construction of the space shuttle. • Provides excellent shock absorption and cushioning, reducing pressure on heels, knees, and ankles for daily comfort. • Anti-fatigue insoles that reduce fatigue in jobs that require standing or walking for long hours. • Help reduce pain in cases of plantar fasciitis or heel spurs. • Easily adapt to shoes, sneakers, boots for all-day work, athletics, casual, travel, hiking, climbing, etc. • Machine washable insoles.