Panasonic introduced several new headphones at International CES, held earlier this month, including what its calling the world's first high-fidelity in-ear headphones made of Zirconia.

The RP-HJE900 are engineered with Zirconia, making them increasingly durable, Martha Whiteley, a Panasonic spokeswoman, told TWICE, and providing less resonance than materials like plastic or aluminum. They are meant for long-term use and come with detachable wires to allow for this.

Other features include a frequency response of 6Hz to 26kHz, sound pressure sensitivity of 100dB, impedance of 26 Omega and 12.5 mm drivers. The cord also has a slider to prevent tangling.

They are scheduled to be available in May in either black or white for a $229 suggested retail.

Panasonic also introduced the RP-HJE700 in-ear headphones, which reportedly use a triple virtual speaker system that uses three tuning gates. The speakers feature special ribbing on the driver cones to provide rigidity for purer sound and less resonance, and the limb-mounted diaphragm is meant to enhance the cavity capacity to deliver a wider dynamic range.

They are constructed of solid aluminum housing and feature neodymium magnet. Frequency response is listed as 6Hz to 26kHz, with a sensitivity of 106dB, impedance of 16 Omega and 12.5mm drivers.

They are scheduled to be available in black or silver in May for a $129 suggested retail.