Delivery very fast! And without tariffs or mail. Such as described. as works perfectly, with good frequency response, beautiful and very comfortable for me. Will Test with the band and add your efficiency as IEM. Believe go answer well… Both work perfectly. Using as return it sounded good for my hearing. Are two guitarists in band using this, we hear claramenre all instruments and voices, with emphasis on bass. Which greatly facilitates the monitoring on Heavy Metal. Used by more than 1 hour continuous without any discomfort auditory or anatomical. Recommend this seller and this product, will return to buy for sure ....