From mountain trails to morning yoga class, our Standard Mouth Insulated Sport Cap lets you hydrate one-handed and on the fly. It’s the first insulated sport cap specifically designed to keep water in your Hydro Flask bottle ice cold, sip after sip.

Please note: This lid is not leak proof.

Compatible with all Standard Mouth bottles
Insulated for enhanced temperature protection
Quiet, "no whistle" valve
BPA-Free and Phthalate-Free