Sumajin's best-known for its inexpensive but well-made silicone cases, and it's dabbled in canalphones and clip-on earphones before, so now it's branching out into something new: on-ear headphones. Turbo ($35) is the name for its series of 40mm-driver-equipped glossy plastic headphones, which come sparingly packaged in blister wrap and include a traditional iPod/iPhone/iPad-friendly 3.5mm headphone plug at the end of a long cable. Five color…
