If you want one steel sports watch that handles business trips, weekend hikes and everything in between, the Spirit Zulu Time 39mm on its matching bracelet is a compelling answer. It pairs a highly legible black dial with a genuine GMT function, and the all-steel build means there is no strap to baby in the rain or at the pool.

Longines has a long relationship with flight. The brand supplied instruments to pioneering aviators, and in 1925 it produced its first dual-time-zone wristwatch, the ancestor this collection is named for. Zulu refers to Z, the radio letter pilots use for Coordinated Universal Time. Under the dial of reference L3.802.4.53.6 sits caliber L844.4, a Longines-exclusive automatic with a silicon hairspring for magnetic resistance and official COSC chronometer certification.

The 39mm case is 0.4mm slimmer than its 42mm sibling, and on the wrist it feels compact and balanced. The bracelet closes with a double safety folding clasp that you open by push-pieces, and it can be swapped for a strap in seconds thanks to the quick-change system.

Technical Notes: Longines L3.802.4.53.6

• Diameter and height: 39mm by 13.5mm in stainless steel
• Dial finish: matte black, luminous applied numerals, date window at 6
• Rotating bezel: bidirectional with black ceramic insert for the second time zone
• Caliber: L844.4 self-winding, true GMT with independently set hour hand
• Autonomy: up to 72 hours at 3.5 Hz
• Certification: COSC chronometer
• Water resistance: 10 bar, screw-down crown
• Bracelet: stainless steel, push-piece folding clasp

Practical, precise and rooted in aviation history, it is a GMT built to be worn hard.