Each kit includes a selection of Bivar’s most popular light pipes:
Panel Press-Fit kit (right) is has rigid light-pipes up to 35mm long that attach to the front panel in various ways – inlcuding nuts and press-fits – and protrude directly backwards.
Some of these also protrude forwards a little too, with shaped ends to push light in various directions, and some are IP rated too.

‘ZeroLightBleed’ design kit (left) has light pipes that attach at the board end and, according to Powell: “represent an adapter which includes built-in surface mount LED”. They “provide maximum light transmission by channeling light directly to the lens”.
Included in this kit is a pair of model UHF5-6.000-Y-67 flexible silicon light pipes which can snake ~150mm from board to panel.
Electronics Weekly