As for extras, the SE425 earphones include the usual suspects. You get a hard-sided, zippered carrying case, an earwax-cleaning tool, and a quarter-inch adapter. Plus, there's Shure's standard fit kit with three sizes (S, M, L) of the flex and black foam sleeves as well as one pair of triple-flange and one pair of universal-fit yellow foam sleeves.
Of course, sound quality is perhaps the chief concern for a pair of earphones costing several hundreds of dollars, and the SE425s don't disappoint in this department. We wouldn't expect them to, either, given the fact that they feature the same impressive internal technology found in the SE420s. The earpieces cram in dual High-Definition MicroDrivers, which means that each one has a dedicated tweeter and woofer.
Music piped through the Shure SE425 earphones sounds fantastic, pure and simple. The earbuds offer excellent passive-noise isolation, and the seal of this design allows for deep, tight bass response--it's enveloping without being overwhelming, and there's no distortion. The highs are sparkly, and music overall has impressive clarity; even during frantic hard rock riffs, we could pick out the varying sounds. No detail is lost, and mids provide the warm richness we crave across the board. There's not a particular genre that stands out here, so if you have eclectic listening tastes, rest assured that the SE425s will not disappoint.