With Merrell's 25 years of experience in women's footwear, the Siren 4 Thermo is designed to fit the distinct contours of women's feet, providing comfort, support and stability on even the longest hikes, with added insulation of 200 grams providing warmth and protection. Now equipped with new SOLARCORE® insulation, a lightweight material originally designed for NASA, you'll never have to worry about the cold again.
The all-new center zipper makes it easier to put on and take off, a new improvement that comes directly from consumer suggestions. The Merrell waterproof upper will keep your feet dry. Thanks to the Vibram® IceTrek® outsole, traction remains consistent even in the wettest and slippery conditions. For the first time, we offer Vibram® lug traction for improved grip on uneven terrain.
The all-new center zipper makes it easier to put on and take off, a new improvement that comes directly from consumer suggestions. The Merrell waterproof upper will keep your feet dry. Thanks to the Vibram® IceTrek® outsole, traction remains consistent even in the wettest and slippery conditions. For the first time, we offer Vibram® lug traction for improved grip on uneven terrain.
- Waterproof membrane seals out water and lets moisture escape
- Waterproof full-grain leather and knit upper
- 100% recycled laces and straps
- Heavy-duty YKK middle zipper for easy on and off
- Gusseted tongue keeps debris out
- Protective, abrasion-resistant rubber heel and toe cap
- 100% recycled fleece lining
- 200 grams of Primaloft® Gold Eco Series synthetic insulation
- SOLARCORE® insulation with Airgel provides superior warmth underfoot while being extremely flexible and ultra-thin
- 100% recycled mesh sole cover
- NXT treated to prevent odors
- Removable 5% recycled PU footbed
- FloatPro™ foam midsole for lightweight comfort that lasts
- Vibram® Icetrek outsole designed to provide better grip on very cold, icy or snowy surfaces