We have been making these 24V 2D light fittings for over 25 years. Using our highly efficient inverter circuit, the light uses approximately 0.5A on a 24V circuit. The light includes a 16W 2D tube in this fitting.
We also make these with a 10W 2D tube, using the Duralamp tube.
These lights are for 24V use only (allowing for the fluctuations in voltage on 24V leisure circuits), we also manufacture a 12V version too.