Adorama offers the Sennheiser CX 475 Premium In-Ear Noise Blocking Headphones in Black for $19.99. This $5 mail-in rebate cuts it to $14.99. With free shipping, that's $2 under our June mention, $10 off list, and the lowest total price we could. They feature a 19Hz to 25kHz frequency response, 120 dB sensitivity, and 3.5mm jack. Rebate expires October 27.