4mm thickness. Superfeet FLEX insoles offer long-lasting comfort for most footwear.MoistureWick™ with Odor ControlReduces Foot FatigueThe structured heel cup positions the soft tissue to help with natural shock absorptionThe flexible heel cradle and contoured foam provide the shape that supports the foot and arch. It’s this distinct shape that separates Superfeet insoles from any otherSuperfeet’s durable construction keeps its shape, delivering reliable support for up to 12 months or 500 miles – whichever comes firstBacked by Superfeet’s 60-Day Satisfaction Guarantee FEATURES: HEEL CUP: The structured heel cup helps stabilize and support the foot and positions the soft tissue underneath the heel to help naturally absorb impact. BIOMECHANICAL SHAPE: The contoured shape helps stabilize and support the foot, which may help reduce stress on feet, ankles and knees. FLEXIBLE HEEL CRADLE: The flexible horseshoe-shaped heel cradle provides structure and stability to the foam layer. ROUNDED EDGE: The rounded edge on the full-length foam layer improves the fit in footwear. 4mm AEROSPRING™ FOAM: Durable viscoelastic closed-cell foam absorbs impact to deliver long-lasting comfort.