The heavier sleeve: insulation that zips closed over the whole bottle rather than an open tube, with a rubberized hook and a handle so it can hang off a pack or a seat back. Nalgene’s claims for it are that it insulates hot and cold and prevents condensation.

What it fits — and what it does not

Nalgene publishes no compatibility field for this sleeve at all. What exists is Nalgene staff answering customer questions on their own product page, and we are passing that on as what it is rather than as a specification: they say it was designed for the 32 oz wide mouth, that the 32 oz wide mouth and the MultiDrink fit, that the narrow-mouth 32 oz fits — and that it will not fit the On-The-Fly cap. That last one is the detail worth knowing before you order.

Specifications

• Designed for the 32 oz Nalgene wide mouth
• Zip closure, full bottle coverage
• Rubberized hook and carry handle
• Country of origin China
• Material — not published in Nalgene’s specifications
• Insulation type — not published
• R-value or hours-cold rating — not published

No performance numbers, and we are not going to supply any. Nalgene publishes no R-value, no temperature range and no “keeps cold for X hours” claim for this sleeve. Their reviews contain the usual anecdotes about water not freezing overnight; those are customers, not a rating. A customer also asked them directly whether it contains PFAS and Nalgene did not answer — so there is no PFAS-free claim here either, in any direction.

Why there is no weight above. Nalgene prints the same 4.8 oz figure on every sleeve they sell — plain, insulated and zippered alike. That is a default value in their data, not a measurement, so we have left it out rather than repeat it.