Firmware v2.06.03 is available for:

NDL-2810R
NDL-21085T
NDL-2800SR+
NDL-21200R(-PRO), 21600R(-PRO)

NDL-2455R
NDL-2471R
NDL-2555T
NDL-2755T

NDL-2800R-PRO2

Firmware V3.02.04.60 (OS7) is available for:

NDL-2480R
NDL-2491R
NDL-2580T