The OKY3465-3 is a button module manufactured by OKYSTAR. It measures 25.8x28.1x5mm in size and is designed to be used with the D1 mini. This module is typically used to control input/output signals and provide tactile feedback when activated. It is a push button and is made of a PCB with two conductive contacts. When the button is pressed, the two contacts make or break a contact, allowing the signal to pass to the output.