Buy Relay Switch -

A stackable shield for Arduino that adds four independently controlled 2A relays. Available for $28.40 at DigiKey or $32.65 at RobotShop . 1 Channel Relay Module 5V DC Goliath Automation & Robotics& more Go to product viewer dialog for this item.

A heavy-duty, single-pole relay with blade terminals. Available for $6.99 at Northern Tool or $8.75 at Summit Racing . OLS Waterproof Relay Switch Harness Set TrueMods& more Go to product viewer dialog for this item. buy relay switch

An industrial solution for motor loads up to 1.5hp. Available for $41.30 at Grainger . A stackable shield for Arduino that adds four

Relay switches are categorized by their application, ranging from smart home automation to heavy-duty industrial or automotive use. When choosing a relay, ensure the matches your control signal (e.g., 5V for Arduino, 12V for cars) and the contact rating can handle the power of the device you are switching. Smart Home Relays A heavy-duty, single-pole relay with blade terminals

Supports higher loads up to 16A and includes built-in power monitoring. Available for $27.99 at Walmart . Shelly 2PM Gen4 Smart Relay Switch 2-Channel Shelly USA& more Go to product viewer dialog for this item.

A dual-channel relay for controlling two circuits or motors like roller shutters. Often sold as a 2-pack for $70.50 $56.40 at Shelly USA . Automotive & 12V Relays