Overview Product Description Nalgene Narrow Mouth Replacement Loop Cap Blue N/MNalgene narrow-mouth replacement caps < - Narrow-mouth, loop-top replacement cap- Fits: 38mm openingsClick here to view our entire selection of Nalgene products Product Videos Custom Field Product Reviews Write a Review Write a Review × Nalgene Nalgene Narrow Mouth Replacement Loop Cap Blue N/M Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *