This low-profile "sub kit" consists of a type TL750L05CLP, fixed 5 V, 150 mA low-dropout (LDO) voltage regulator, plus 0.1 uF and 10 uF capacitors that are normally used with it. You can use this to generate 5 V DC from a 9 V DC power supply, for example. The absolute input range is about 6-26 V, but please see the TL750L05CLP datasheet (available here) for complete details.
This little sub-kit is offered here as an accessory to our Diavolino kits, in case you'd like to power one from higher than 5 V.
