First things first, what the heck is going on with the way he's holding that phone? He looks happy with the conversation but then he's a model and there's probably nobody on the other end. He's selling those fishnet undies, or rather the knitting pattern for sewing/knitting this underwear up yourself. Patterns could have been ordered in chest sizes Size: 38, 40 or 42. The gent below is shaving in his shorts and has an equally nice physique. The health benefit was because air traveled through.
Another company from Europe (the above Strutt's ad was from England) offering this unique garment was Twilley's. They offer a noted sportsman in their ad but don't show him in the boxers like the Strutt's ad model does. These items were promoted for sportsmen between the late 1950s and mid 1960s. The instructions for sewing reportedly included options for making the cotton pouch which could be adjusted into boxers as well.
