Siren 4 Thermo Mid Zip Waterproof Flip Flops and increases circulation to help

and increases circulation to help users move and feel better

FABRIC: 88% Polyester-recycled 12% Elastane

Original BIRKENSTOCK footbed: anatomically formed

87% Recycled polyester strobel board

which is softer and stronger than others

Siren 4 Thermo Mid Zip Waterproof Flip Flops and increases circulation to helpA winter ready boot with a women's specific fit that combines function and all day wear ability. Best for: Winter HikeInsulation: 200 grams Primaloft Gold Eco Series synthetic insulation. SOLARCORE Aerogel insole provides underfoot superior warmth while being extremely flexible and ultra thin. Waterproofing: Waterproof full grain leather upper, complete with a waterproof membrane seals out water and lets moisture escape. Traction: Vibram Arctic Grip