Icebreaker Siren sleeveless base layer

The ICEBREAKER Siren Sleeveless Base Layer offers year-round comfort and versatile styling. Crafted from a soft, stretchy merino wool blend, this thermal tank top naturally regulates temperature, keeping you warm or cool as needed. Its sleek, feminine design with a round neck ensures a smooth, bulk-free fit under other layers or as a standalone piece. Perfect for active pursuits and everyday wear, it provides natural odor resistance for extended freshness and unrestricted movement. This ultralight, essential layering piece is designed for ultimate next-to-skin comfort