Excellent item, fast delivery. Thank you.
Do NOT purchase this item. I left feedback before I used the board as I anticipated it would work fine. However it only boosts voltage to 5v temporarily when the button is pressed and then the voltage depletes rapidly 15 seconds later, in my case to 3.4v. It also depleted a fully changed lipo battery to 2.5v within 1 hour - even though the device wasn't powered on. This is dangerous and could cause a fire!
Delivery to Korea took 45 days. Thank you.