Tuli's Heavy Duty Heel Cups are the most advanced shock-absorbing heel cups available today. The primary force of the heel strike is absorbed by the larger and higher waffle pattern while the lower and denser waffle pattern absorbs the "high pressure" and final force spike of heel strike. Twice as thick as Classic Heel Cups, they are perfect in athletic shoes or more spacious lace-up shoes (like work boots, athletic shoes, etc.) Ideal for sports enthusiasts who play hockey, soccer, volleyball, basketball and tennis.