VMInnovations offers the Sennheiser adidas MX 680 Sports Earphones for $39.95. Coupon code “SEN19OFF” trims it to $19.99. With free shipping, it’s the lowest total price we could find by $14. Features include DuPont Kevlar reinforced cables, sweat and water resistant construction, built-in volume control, various custom fit silicone earbud adapters, frequency response of 18Hz to 20KHz, and more.