Duo Ear Plugs Mfg Number:  12640 UPC Number:  023614181842 Insert yellow end for variable level protection, such as outdoor ranges Use olive end for a constant NRR of dB (indoor ranges) Selected for use by US military and NATO SALES@ABLEAMMO.COM | 1-800-720-3275 | Thu 23 May 2013 03:11:58 PM MDT