With 25 years of Merrell's women's-specific fit, the Siren 4 Thermo is uniquely engineered to cradle the distinct contours of female feet, providing comfort, support, and stability even on the longest hikes with added insulation for warmth and protection.

• Waterproof membrane seals out water and lets moisture escape

• Waterproof full grain leather and wool upper

• Bungee lace with toggle closure for a secure fit

• 60% recycled laces

• Bellows tongue keeps out debris

• Protective and abrasion resistant rubber heel and toe cap

• 100% recycled fleece lining

• 200 grams Primaloft® Gold Eco Series synthetic insulation

• Rock plate for protection

• FloatPro™ Foam midsole for lightweight comfort that lasts

• Vibram® Icetrek outsole designed to provide the improved grip on very cold, icy, or snowy surfaces

Mesh and TPU upper

Foam and rubber soles