Power Bank Module 3.7V Li-ion Battery Micro USB to USB A Power Apply Module 5V 1A Charge Module

From the shop's description

Features This PCB supports charging the battery, simply supply a 5V Micro-USB source to the charging input and it will charge the connected battery to 4.2V. Great for mobile power source using Lithium-ion batteries (unprotected is also ok). Connect multiple batteries to the battery input to increase the capacity power capacity. Charging voltage input: 5V 1A Step up voltage output: 5V 1A max Transient current: 180uA Red LED: Charging Green LED: Charging completed Blue LED: There is a load in the USB Size: 50 x 20 x 9 mm