The Seiko 5 is a line of automatic (self-winding) wristwatches known for their durability, reliability, and affordability. The "5" in the name represents five key features: automatic movement, day-date display, water resistance, a recessed crown at the four o'clock position, and a durable case and bracelet. Several sources say that the Seiko 5 has been a popular choice for everyday wear and a good entry point into mechanical watches.