Keep your vehicle's electrical systems running smoothly with this pack of 5 DC 12V 40-Amp 4-Pin SPST automotive starter relays. Designed as reliable replacement relays, these compact units feature copper contacts for consistent conductivity and an 80-ohm coil resistance that ensures stable, dependable switching performance. The single-pole single-throw (SPST) contact configuration delivers straightforward on/off control for a wide range of automotive electrical circuits. Installation is hassle-free thanks to the quick-connect plug-in mount design, requiring no special tools to get up and running. Each relay measures 2.45" in total height and operates automatically at a minimum switching voltage of 12V DC, handling up to 40 amps of current with a coil wattage of just 1.8 watts. The durable plastic housing with integrated mounting bracket makes securing the relay in your engine bay simple and secure. With five relays included in the pack, you'll have convenient backups on hand for multiple vehicles or future projects. Backed by a one-year warranty, these relays are a smart, practical choice for DIY mechanics and automotive enthusiasts alike.