This Earphone

JandR.com has the Sennheiser MX75 Sport Line Stereo Headphone for $19.99 with free shipping.

Product description from JandR.com:

Twist-To-Fit System / Sweat Resistant / Ergonomic Design / Improves the sound of your MP3 player / Designed for active lifestyle users

The Sennheiser MX75 Sport Line Stereo Headphone has an innovative holding system for a better and more comfortable fit. You’ll get more det
ailed sound, with an extra-rugged cable for use while at the gym or on the road. Sennheiser’s exclusive Twist-to-Fit holding system for a secure fit in the ear. The moisture-resistant construction makes these Headphones the ideal sports companion.

Special Twist-To-Fit System ensures best possible fit

Powerful neodymium magnets for detailed sound

Rugged earphones and cable

Sweat and water resistant

Comes with ear Adapter set, cable clip and flexible vinyl carrying case

Weight: 4.8 oz.

Product link.