The headband is a masterpiece of utilitarian design. It often features a stainless steel spring mechanism encased in a leather-wrapped or padded strap. The adjustment sliders click into place with a reassuring authority that modern grooved plastics simply cannot replicate. There is a sense of "heft" that instills confidence; these are headphones built to survive decades, not just a warranty period.
If you have found a pair of Sony DR-11 headphones in a thrift store or inherited them from a family member, here is how to bring them back to life: sony dr-11 headphones