Sennheiser - #TB: In 1968, Sennheiser launched the HD 414, the world's first open-back headphones, which remain the bestselling full-size headphones of all time. Did you know that we still stock spares
Sennheiser HD414 1960' | Reverb
Sennheiser+HD+414+Headband+Headphones+-+Black%2FYellow for sale online | eBay
Happy April 14, or HD 414 Day! : r/headphones
Can Sennheiser's iconic headphone compete with today's models? - CNET