Sennheiser CX200 Twist-To-Fit Earbuds for $14.99 shipped after coupon code EMCYTZT830.  It is valid on 10/15 only.  Here is a screenshot for your reference.  It features twist-to-fit system for better fit with bass driven stereo sound and high passive attenuation of ambient noise.  Most places have it for about $23 or more.