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Choose the build

Find your weight.

Choose the balance of cushion, warmth, and bulk that fits your conditions.

Temperature control

Temperature control

Helps feet stay comfortable across changing conditions.

Dry Comfort

Dry Comfort

Moves moisture away for dry comfort through long wear.

Freshness Support

Freshness Support

Helps keep feet fresher longer through repeated wear.

Engineered Durability

Engineered Durability

Built for repeated use - reinforced for extended wear.

Lifetime Warranty

Lifetime Warranty

If they wear out, we replace them. No expiration.

Pick the build

Three weights. Three ways to perform.

From warm and active to cold and demanding, there's a build for every condition.

Lightweight
Minimal bulk. Maximum versatility.
Breathable, lower-bulk performance for warmer conditions, movement, everyday wear, work, and sport.
Available Heights
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Shop Lightweight
Midweight
The all-around sweet spot.
More cushioning and warmth without excessive bulk. Ideal for changing conditions, hiking, boots, travel, and everyday outdoor wear.
Available Heights
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Shop Midweight
Heavyweight
Maximum warmth. Maximum cushion.
Built for cold weather, rugged conditions, tall boots, and extended time outdoors.
Available Heights
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Shop Heavyweight

Which weight is right for you?

Feature Lightweight Midweight Heavyweight
Bulk Lowest Moderate Highest
Cushion Light Medium Maximum
Warmth Light Balanced Maximum
Best conditions Warm / active Changing / cool Cold
Everyday wear Excellent Excellent Specialized
Boots Yes Excellent Cold-weather boots
Athletic Excellent Some uses Not primary

Built for hard wear.
Backed for life.

If they ever wear out, we replace them. No expiration. That's the Altera difference.

American Made

Proudly made in the USA

Natural Performance

Alpaca fibers deliver real performance benefits.

Trusted by Thousands

Thousands of 5-star reviews from real customers.

Easy Returns

30-day returns and exchanges.

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