Personal On-Ear Stereo Headphones in Green. The HamiltonBuhl personal on-ear headphone is the ruggedly constructed, robust yet lightweight headphone ideal for todays tech filled classrooms. With the ever growing classroom technology, each student needs a high quality, durable yet comfortable headphone to get the most out of their high tech lessons and the HA2 headphone not only provides rugged durability and high quality sound, but the lightweight, on-ear design allows for all-day comfort and easy compact storage.