Men's Sonicblast (400 - Winter Sea/Stillwater) Size:9 Polartec® Power Dry® brief liner:

Polartec® Power Dry® brief liner: 89% polyester & 11% spandex

Measure circumference just below patella (knee cap)

Maintaining the same responsive

A comfort-driven style designed for downtime

Altra went all in on tech so you can go all out on the trail

Men's Sonicblast (400 - Winter Sea/Stillwater) Size:9 Polartec® Power Dry® brief liner:The SONICBLAST shoe offers a lightweight and responsive ride that makes it functional for tempo runs and your daily training. The midsole features a two layered foam with FF BLAST MAX and FF TURBO cushioning to help create a lightweight, bouncy, and advanced cushioning running experience. Additionally, an ASTROPLATE propulsion mechanism is centered in the foam. This helps propel your momentum forward, creating a faster feel underfoot. Style 1011C083