A compact breadboard‑friendly rotary encoder module delivering 20 pulses per revolution with precise directional detection. Operating from 3–5 V, it offers left/right output signals and integrates a 10 kΩ pull-up resistor for stable signal integrity—ideal for embedded control interfaces.

A compact 6 mm red laser diode module emitting a bright 650 nm dot at 5 mW, powered by 5 V supply with internal current limiting. Features brass housing, simple two-wire connection (red +, blue/black −), and a continuous spot ideal for embedded and pointing applications. 

A compact 5 V tactile push-button module featuring three I/O pins and ultra-low contact resistance (<50 mΩ). Designed for up to 100,000 actuations with a tactile force of approximately 180–230 gf. Engineered for durability across -25 °C to +105 °C environments—ideal for Arduino and embedded control interfaces.

A compact micro‑USB Li‑ion battery charger module using the TP4056 chip. Operates from 4.5–5.5 V, delivers 1 A charge (adjustable via R‑prog resistor), and charges an 18650 cell to 4.2 V with ±1.5% accuracy. Red LED indicates charging; blue LED signals full charge. 

A high-volume 3–24 V piezo buzzer with 95 dB output at 10 cm, housed in a compact 38 mm × 22 mm enclosure. Includes two units per pack, with simple red (+) and blue/black (–) wiring. Ideal for alarms, notifications, and electronic alerts. 

Compact RS‑232‑to‑TTL converter module using MAX3232 driver, compatible with 3.3–5.5 V systems. Features standard DB9 interface and easy connection via TXD, RXD, GND, and VCC pins. Ideal for MCU programming, GPS, set‑top boxes, and legacy communication link integration.

Compact boost converter module that charges and protects single-cell Li-ion batteries (3.7–5.5 V input) while stepping up output to 5 V at 1 A. Features charge/discharge indicators (LEDs), integrated management, and multi-fold protection—perfect for DIY power banks and portable charging systems. 

A single‑channel relay timer module featuring optocoupler isolation and industrial-grade circuitry. Users can configure timing and cycle parameters—such as OP (on time), CL (off time), and LOP (loop count)—which are saved automatically upon power interruption. The relay uses passive contacts for line control. 

A compact 5 mm glass-encased mercury tilt switch using a mercury ball to complete or break circuits as the device tilts. It operates as a low-cost normally-open inclinometer and offers spark-free, silent switching—perfect for orientation detection in robotics, safety systems, and industrial applications. 

A high-efficiency XL4015A step-down converter module offering adjustable output from 1.25 V to 36 V, with an input range of 4–38 V. Supports constant current (CC) and constant voltage (CV) charging up to 5 A (75 W), featuring low ripple and robust protection features. 

A precision 100 A / 75 mV DC shunt resistor made from manganese-copper alloy. Delivers accurate current measurement (0.5% class accuracy) for digital or analog ammeter modules like VAM28. Dimensions ~104 × 21.6 × 2 mm—ideal for panel mount current sensing applications. 

A high-efficiency TP5100 charging module supporting single (4.2 V) or dual-cell (8.4 V) lithium batteries. Offers programmable current up to 2 A, wide 5–18 V input, and three-phase charging (pre-charge, CC, CV). Includes LEDs for status and integrated protections for safety.