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All socks/Randy Sun

Randy Sun THERMO Merino Waterproof

Blend Inner: 64% merino wool, 26% acrylic, 7% polyester, 3% elastane; Outer: 71% polyester, 12% acrylic, 7% nylon, 5% wool, 5% elastane

Separate blends for each layer.

no height published, drawn at a typical heightpadding: the maker doesn’t say where · Waterproof membrane

The footwear outline is schematic. Check the cuff with your own shoes.

View at Randy Sun ↗Compare this sock

When you want a waterproof membrane for wet trails

A waterproof sock with an inner layer of 64% merino wool.

Keep in mind: Water can still get in over the cuff, and the three layers take more room than a standard sock, so try it in your shoes before a wet trip.

Closest in Randy Sun’s range: the PROSHIELD Merino Knee High Waterproof. They differ in cuff and blend; the size chart is the same.

This sockPROSHIELD Merino Knee High Waterproof
CuffNot publishedknee high
BlendSeparate blends for each layerSeparate blends for each layer

Compare the two side by side

Materials, padding and sock type

Waterproof membrane · cushion not published

None
Light
Full
Extra
Padding shown schematically. Brand labels do not share a thickness scale.
Exact model
Randy Sun THERMO Merino Waterproof
Style number
RS329 / RS340
Size chart
Unisex chart
Cuff height
height not published
Weight (maker’s term)
Not published
Cushion (maker’s term)
Not published
Cushion location
Not published
Sock type
Waterproof membrane
Layers
3
Material blend
Separate blends for each layer
Wool-free
No, contains wool or alpaca fiber
Facts from
Randy Sun’s US site

Inner: 64% merino wool, 26% acrylic, 7% polyester, 3% elastane.

Outer: 71% polyester, 12% acrylic, 7% nylon, 5% wool, 5% elastane.

Between the inner and outer knits sits the middle layer of Randy Sun’s DROPZERO system, printed as a 100% PU membrane, PFAS free.

What Randy Sun says about it

“Combined with a waterproof-breathable 3-layer construction, it helps keep feet warm and dry while blocking cold wind and moisture.”

“Waterproof-Breathable DROPZERO System”

The maker’s own words from its product page; not tested by HikingSocks.guide.

Cushion and weight labels are this brand’s own terms. They are not a shared thickness or temperature rating.

XS
S
M
L
4.56810121415.5

US men’s

Bands follow this chart’s published ranges. XS: 4.5–6.5 · S: 7–10 · M: 10.5–13 · L: 13.5–15.5

Check the size and the shoe together

Start with the unisex chart for this exact model. Use the size lookup or the whole Randy Sun size chart to find the published range, then check the heel position, toe room and cuff in your footwear.

The maker does not give a heel-to-cuff measurement. Try the socks with your boots to see whether the cuff sits above the collar. See how sock heights differ.

Try the complete layered construction, not only one layer. Extra fabric can change toe room and pressure inside the shoe. The footwear-fit checklist explains what to check.

Care for the exact pair

Machine Washable: Turn inside out. Wash on a gentle cycle below 40°C (104°F). Use standard liquid detergent; avoid fabric softeners or bleach. Hand Wash: Gently rinse under lukewarm water to remove mud or sand. Do not wring or twist excessively. Gently press out excess water. Drying Protocol: Drip dry naturally in a well-ventilated, shaded space. Do not tumble dry, iron, or dry clean. High heat is the enemy of waterproof membranes.

Use the care lookup for this model’s wash and dry directions. A general wool routine should not override instructions for a membrane, a two-layer construction or a specific treatment.

Another sock to compare

Both constructions contain animal fiber (wool or alpaca). This changes from waterproof to conventional. The other sock has no waterproof membrane. Check that the changed construction suits your footwear.

Sealskinz Suffield uses its own size chart. Compare the two socks to see where their height, material, cushioning and care differ. Matching specs don’t mean they will feel the same in your shoes.

Two socks to compare with it

Same size chart

Randy Sun PROSHIELD Merino Knee High Waterproof

knee high · not specified. Your Randy Sun size carries over.

Compare side by side

Same cuff height

Sealskinz Suffield

Sealskinz · height not published · not specified.

Compare side by side

Find similar socks

Product sources

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