Sonic Electronix offers the Klipsch Reference S4 Premium In-Ear Noise-Isolating Headphones, model no. 1013730, for $44.99 with free shipping. That’s $5 below our mention from three weeks ago and the lowest total price we’ve seen by a buck. (It’s a current low by $4.) Features include four different-sized ear tips, storage case, clothing clip, 10Hz to 19kHz frequency response, and more.