Optosupply 5mm superbright yellow diffuse current regulated LED

These are very nice superbright yellow (590nm) diffuse LEDs from Optosupply which have inbuilt constant current drivers, so you don't need resistors.

Rated output is 3,000mcd at a 30 degree beam angle at a typical current of 14mA.

Use them on their own, or in series with other LEDs to control the current in the whole string.

Part number is OSY5PA5A34A-CRLED14 and datasheet is here.