- Waterproof full grain leather and knit upper with waterproof membrane seals out water and lets moisture escape
- Heavy-duty, Waterproof, YKK medial zipper for easy on and off with a bellows tongue keeps out debris. The protective and abrasion resistant rubber heel and toe cap keep feet safe and secure all day
- 100% recycled fleece lining, 200 grams Primaloft Gold Eco Series synthetic insulation and SOLARCORE Aerogel insole provide superior warmth while being extremely flexible and ultra-light
- FloatPro Foam midsole for lightweight comfort that lasts
- Vibram Icetrek outsole designed to provide improved grip on very cold, icy, or snowy surfaces, while the Vibram traction lugs are specifically designed to increase traction and shed debris with each step
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 200 grams of added insulation for warmth and protection. Now equipped with SOLARCORE® insulation, lightweight insulation material initially designed for NASA, you never have to worry about warmth. The all-new medial zipper provides easy on/off, a new improvement made directly from customer feedback. Merrell waterproofing on the upper will keep your feet dry. With Vibram® IceTrek® underfoot, traction remains consistent under the wettest, most slippery conditions. For the first time ever incorporating Vibram® traction lug for enhanced grip on uneven terrain.
- Department : womens
- Date First Available : April 18, 2025
