Recs.
Updated
The PM-3s are closed back headphones with a flat sound signature. This makes them great for music/studio monitoring, or for those who want their music to be as close to the intended mix as possible.
These are fairly compact with great noise isolation, so these can also be used for tracking or for a quality mobile listening experience.
SpecsUpdate
Pros
Pro Very good passive noise isolation
Its closed back design along with the fairly thick, leather-surfaced earpads are very effective at keeping the music in and the ambient noise out. This is very useful in tracking situations, and will also help you focus on the audio even when in a busy, noisy place.
Cons
Con Weight is on the heavy side
The use of metal and quality plastics on the headphone construction, as well as the magnets in the drivers contribute to a hefty weight. While this is not a problem to wear for short periods, you may feel some head or neck strain when using the headphones for hours. This also makes the headphones an extra challenge to bring on the go.