90.2% merino wool, 9.8% cashmere blend. The warmth of merino with the softness cashmere adds on contact with skin.

Long-sleeve design with ribbed polo collar. Sharp silhouette that works through the full cooler season without adjustment.

Slim fit with controlled structure. Sits close without restricting. Holds its shape through a full day of wear.

Clean button closure at the collar. Composed finish that requires no styling effort.

Most knit polos sacrifice warmth for refinement or refinement for warmth. The Siro does not negotiate.

The Siro Polo was built around a blend that earns its price. Merino wool provides genuine insulation and natural breathability. The 9.8% cashmere is enough to change how the fabric feels against the skin without overpromising. Soft without being fragile. Warm without being heavy. The ribbed polo collar and long-sleeve cut give it a silhouette that reads intentional across every cooler month in the calendar.

Diamond built the Siro for the man who wants one knit polo that handles everything from a considered weekend to a sharp casual Friday. Slim fit keeps the silhouette clean. The clean button closure keeps the look composed. Nothing to adjust. Nothing to overthink.

The Siro. Refined for every cooler day.

Material and Care

90.2% merino wool, 9.8% cashmere.
Hand wash cold recommended. Lay flat to dry. Do not tumble dry. Do not iron directly on knit. Store folded, not hung, to preserve shape.

Shipping

United States and Canada: Next business day processing. Free shipping on orders over $100.
Australia and New Zealand: 5 to 8 business days. Free shipping on orders over $150.
Rest of the world: 7 to 10 business days. Free shipping on orders over $150.
For full details, see our Shipping page here.

Pay in 4 interest-free installments with Afterpay.