Nichia 300B, 310B and 320B Series LEDs The 300B, 310B and 320B LEDs, from Nichia, are a family of single colour through-hole LEDs. They have a 3mm (T-1) package with a clear lens. Available in both colour or cool and warm white options, the 3x0B series are suitable for applications such as portable light, signage and decorative lighting.