Free CX 180 in-ear headphone via mail-in rebate with the purchase of any Sennheiser Aviation Headset. Limit of one (1) free CX 180 per eligible Aviation headset purchased. No limit to the number of submissions per customer or household. Free CX 180 is not permitted for resale. Offer valid only on purchases made between November 9, 2009 and December 31, 2009 from an Authorized Sennheiser USA dealer and only after 30 day money back return period for the Aviation headset has expired without return of the headset. Offer valid to U.S. addresses only, for new product only. Internet auction site purchases are excluded from this offer. Mail-in rebate claim forms must be postmarked no later than 01/30/10. Sennheiser distributors, retailers, their employees or their families may not claim rebates on behalf of themselves or on behalf of other end users. Rebate requests not including proper documentation (this official form and dated sales receipt containing model # and retailer’s name) will be ineligible. Rebate eligibility as determined by Sennheiser is final. Sennheiser is not responsible for lost, delayed or misdirected mail. Sennheiser reserves the right to terminate the program at any time. Void where prohibited by law. Sennheiser is a registered trademark. All rights reserved.