The Pioneer SE-100 is a pair of dynamic over-ear headphones that were released in the late 1970s. They are known for their comfortable fit and robust sound quality, featuring a closed-back design that helps to isolate external noise. The SE-100s are equipped with a 40mm driver, which contributes to a rich audio experience, making them suitable for various genres of music. The design includes an adjustable headband and plush ear pads for added comfort during extended listening sessions.