A G4-21L ArrayThe arrays are not cheap but the current draw is low (I measured around 1 amp for all five lights) and their light is certainly more even, the 2D tubes with their built-in inverter cause a shadow in the centre of the fitting.
Before - 2D fluorescent tube
After- Energy saving LED array
To carry out the conversion I had to dump the original innards of the lights and place the array in the centre of the plastic housing. I managed quite a neat installation using two self-tapping screws to hold the array in place and a handy lump of Blue-Tack acting as a spacer to protect the components on the underside of the circuit board. The units run cooler. The old fluorescent units generated quite a bit of heat, presumably because of the inverter installed in each unit. One of the old units had also developed an annoying fault - going off randomly and then coming on again a few minutes later. I hope the LEDs are reliable.