Stowa
Flieger Flieger Logo Datum— lug 20mm

The Stowa Flieger Logo Datum has a lug width of 20 millimetres. Stowa selected this measurement to maintain correct proportions between the 40mm case diameter and the lugs, adhering to German aeronautical design principles. To verify that a strap is compatible, measure the internal spacing between the two lugs using a digital calliper: the value must be 20.0 ± 0.2 mm.

Your choice depends on intended usage. For formal elegance: a vegetable-tanned calf leather strap that will develop patina over time, or alligator for the geometric refinement of its grain. For operational use and absolute water resistance: a ballistic nylon NATO in neutral colours (black, grey, navy blue) that references the watch's aeronautical heritage. FKM rubber is ideal for hot and humid environments, maintaining a lower skin temperature at the wrist.

The Flieger Logo Datum uses standard 20mm spring bars. To change the strap: (1) obtain a spring bar tool or small metal lever; (2) hold the watch with one hand, resting it on a soft surface (leather, microfibre cloth); (3) gently press inward the spring at the base of the first lug and release the strap; (4) repeat on the other side; (5) insert the new strap by aligning one lug first, then press the other until it clicks. Avoid sudden movements to prevent exceeding the spring's flex limits.

All straps with a 20mm lug width are compatible with the Flieger Logo Datum. Milano Straps offers a specialised selection for this measurement: Italian vegetable-tanned leather, alligator, FKM rubber, and ballistic NATO in various colours. Always verify the lug width before purchase and select strap thickness based on material type: vegetable-tanned and alligator leathers require a thickness of 1.4–1.6mm for correct seating, while ballistic NATO is more forgiving.

Durability depends on material, usage, and maintenance. A vegetable-tanned calf leather strap, worn daily, maintains structural integrity for 3–5 years; colour and patina will change, which is desirable. Alligator, being denser and more resilient, may last 5–7 years with the same wear. A ballistic nylon NATO strap can last indefinitely, although colour saturation will fade over time. To extend strap life: clean the strap monthly with a damp cloth, avoid prolonged direct sunlight exposure, rotate use among two or three straps, and do not wear the watch at night or during high-impact sports.