The 4×4 Membrane Keypad is a compact 16-key matrix input device featuring numeric keys 0–9, A–D function keys, and * and # keys. It uses an 8-pin row and column interface for easy connection with Arduino, ESP32, ESP8266, Raspberry Pi, STM32, PIC, AVR, and other microcontrollers. Its thin, flexible design and self-adhesive backing make it ideal for password locks, access control, robotics, automation, menu navigation, and embedded electronics projects.

The 3-6V 400KV High Voltage Generator Boost Module converts a low 3V to 6V DC input into a high-voltage pulse output using an internal boost circuit. Its compact size and simple two-wire input make it suitable for high-voltage experiments, scientific demonstrations, ignition systems, and educational electronics projects. The module requires only a suitable DC power supply and switch for operation.

Warning: This module generates extremely high voltage and should only be handled by experienced users following appropriate electrical safety precautions.

SYN6988 Speech Synthesis TTS Voice Module is a versatile Text-to-Speech module supporting English and Chinese voice synthesis, UART and SPI communication, and up to 4,000 bytes of text input. With standby mode and included USB-to-TTL converter, it is ideal for Arduino, ESP32, robotics, smart home, automated announcements, and voice-enabled projects.