Prospex SPB513J1

The Seiko SPB513J1 employs the robust Caliber 6R55, an automatic movement that offers manual winding, an impressive 72-hour power reserve, and a rate of +25/-15 seconds a day for the sort of everyday reliability that serious collectors appreciate.

The case, crafted from stainless steel, has a subtly elegant 39.5mm diameter and a slim profile of 12mm, making it comfortable yet purposeful. Its curved sapphire crystal, treated with anti-reflective coating, ensures that the sun never interferes with readability.

Rated for 20 bar of water resistance, internal shields protect it from 4,800 A/m of magnetic disturbance, and the screw-down case back adds an extra measure of toughness. The SPB513J1 weighs 154 grams and is delivered on a 197mm stainless steel bracelet that secures with a three-fold, push-button clasp—smooth in operation yet reassuringly secure.