Winter Ultra is an upgraded version of Winter, with improved fit and sound quality. BQEYZ proprietary dynamic + bone conduction hybrid earphones. Improve the filter while still maintaining the best of Winter, giving you a rich low range while enhancing the vocal rhythm. It enhances the curve strength of the housing, combined with the bright blue to create a more beautiful design full of vitality and vitality. Dynamic driver uses PAR (Poly-Allrate) materials in diaphragm combined with dual cavity construction that effectively controls air pressure, creating a resilient low and delicate separated midrange. The bone conductor driver uses PZT (piezoelectric ceramic) material for the diaphragm to achieve a smooth and clear high range without feeling of burr.