Onboard and stable ESP32-WROOM-32E module, -capacity 4M Flash; The I/O ports and UART program download ports of the ESP32 module are all led out, which is convenient for secondary development; Power supply voltage DC5V/7-30V; Onboard ESP32 module IO0 programmable button and reset button; ESP32 supports the use of for IDE development tools, providing reference programs in the development environment; On-board 8-way 5V relay, output switch signal, suitable for controlling loads with working voltage within AC250V/DC30V; On-board 1 programmable LED and relay indicator. type: module Supply voltage: DC5V/7-30V Material: PCB color: blue Size:148 x 79.8mm Package Contents: 1 x Module 1 x Single Row Pin Header 2 x Double Row Pin Header Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.