This is a 10 pack consisting of the MCP1603T-330I/OS and VLS3015ET-4R7M 4.7uH inductor. For a complete regulator you'll need to add additional ceramic caps (if you ping me I can send the ones I've used too). These parts provide a efficient switching solution to convert 5v to 3.3v. I use these parts in the espusb. While the same parts are available from digikey, they tend to be pretty expensive. I purchased these out of Shenzhen at a cost comparable with typical linear regulators. If you'd like to buy in bulk let me know!