Act as a seasoned copywriter with 5+ years of experience in sustainable product marketing. Craft a compelling, 150-word product description for an [eco-friendly water bottle] made from [recycled stainless steel] with a [BPA-free silicone sleeve]. Highlight its unique selling points, such as durability, insulation properties (keeps liquids hot/cold for 12 hours), and environmental benefits (reduces single-use plastic waste). Use persuasive, benefit-driven language that appeals to [eco-conscious millennials], and include a call-to-action encouraging them to 'Join the sustainability movement.' Maintain a friendly yet professional tone, and ensure the description is scannable with bullet points for key features.