By utilizing the LTC3531-3.3 chip, this board will output 3.3v from an input voltage of anywhere from 1.8v to 5.5v and do so with up to 90% efficiency. This board is designed to plug easily into a 2.54mm pitch breadboard.

Here's the datasheet for the LTC3531-3.3: http://cds.linear.com/docs/en/datasheet/3531fb.pdf

Here's a link to the LTC3531-3.3 part on Digikey: https://www.digikey.com/product-detail/en/linear-technology/LTC3531ES6-3.3-TRMPBF/LTC3531ES6-3.3-TRMPBFCT-ND/4729409