Guyot Designs CapCap
Here's what other sites are saying:
The capCAP is a 2-in-1 accessory cap that works with all major wide mouth bottles including Nalgene, Cyclone, Guyot stainless, and many others. A small spout affords splash-free drinking, while the large cap permits easy bottle cleaning and filling with ice. Features an easy-grip rubberized small cap, and a strong, comfortable strap.
- Vargo Outdoors