Looking for a rather long and sleek cabinet for your bathroom? This NuTone Manchester mirrored medicine cabinet would definitely fit that definition I would say. This NuTone medicine cabinet is available at Home Depot where you can find a really wide selection of these different bathroom cabinets in various styles. This particular model would surely fall under "very sleek and simple", and sometimes that's exactly what you want: no fuss, no overly decorative design, just functional and elegant.
This NuTone Manchester medicine cabinet is available both in recessed as well as surfaced mount style. It's certainly important to pick the right one, so you better make sure you check what kind of medicine cabinet you have right now. If you don't have an indention in your wall, then you want to go for the surface mounted cabinet for sure. This particular cabinet is definitely longer than most other, it's definitely a bit of a tricky shape which I'm sure could look really nice in the right setting.
Material: metal I would assume
Style: clean and simple
Fits Where: in the right bathroom
Indoor / Outdoor Conclusion: A touch expensive I would say, however if you were looking for this exact size, then chances are you don't have too many options...
NuTone Manchester 15 in. W x 34 in. H Recessed or Surface Mounted Mirrored Medicine Cabinet
"This Manchester has interior mirrors on the back of the cabinet and the inside door to provide excellent light reflection and versatile functionality. Snap fit shelf supports ensure glass shelves stay in place, but can be easily removed for cleaning. Corner bumpers cushion door for a soft quiet close. Exterior mirror has a 1/2 in. bevel edge."
More info at homedepot.com