The UES Black 60WH Double Honeycomb Thermal is a thicker version of the 60TR Regular Thermal, with the same four-needle flat seam construction for a heavy and well constructed thermal. These work well as a standalone base layer during the modest Fall/Winter days, or a nice heavy initial layer to pile on some flannels and jackets on top of in the darkest of winter days.
Note: Runs small; recommend sizing up one from your typical American brand size for a slim fit, or size up two for a relaxed fit or additional length. For example, if you would wear a L in the UES Extra Heavy Flannels, you would probably wear a L in these thermals for a slim fit. There is some stretch to these thermals, given the fabric, but as they are meant to be a base layer, you should not expect these to stretch and stay permanently stretched. Note that this run (Fall 2022) of thermals run a little smaller than previous year's, so double check measurements if you are basing your size on previous year measurements. These are once washed so there is minimal shrinkage expected. Cold wash, hang dry.
Model: 6'0" and 175 lbs. wearing size XL (two sizes up from his typical tops size) for a relaxed fit. See model wearing L in the Olive here.