Sinn · Instrument Chronographs

Strap for EZM 10 TESTAF

Takes 22 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width22 mm
Case diameter47 mm
Reference950.011
FamilyInstrument Chronographs
MovementSinn caliber SZ01 hours, minutes, small seconds | date | Chronograph
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Instrument Chronographs 950.011

Selected for the 22 mm lug width · workshop selection

All 22 mm straps →

The Instrument Chronographs 950.011, seen from the bench

The Sinn 950.011 is a chronograph designed for harsh environments where reliability exceeds aesthetics. This instrument features a 46.50mm stainless steel case (316L aeronautical standard) with a pilot-style dial and Sinn's patented Ar-Dehumidifying technology. Powered by the Sinn SZ01 chronographic movement, the watch maintains internal humidity below 5% to prevent crystal fogging. The 22mm lug width is a functional choice proportional to the case diameter, requiring straps that meet this specific standard for precise fitting without lateral play.

Frequently asked questions

What is the lug width of the Sinn Instrument Chronographs 950.011?

The Sinn 950.011 features a 22mm lug width, which is specific to this model. This measurement is the result of proportional calculations on the 46.50mm case. To measure the lug width correctly, position a ruler between the internal pins of the lugs: the distance is exactly 22mm. Any strap, whether leather, NATO or rubber, must comply with this standard to ensure precise insertion into the lugs without lateral play or unwanted friction.

What is the best strap for the Sinn 950.011?

Strap selection depends on intended usage. For formal contexts, we recommend vegetable-tanned alligator or Hermès calf, which combine elegance with predictable natural ageing. For a purely instrumental approach true to aeronautical origins, NATO Premium straps in recycled yarn or military Cordura represent the historical solution. FKM (Viton) rubber or technical elastomers are ideal for chemically aggressive environments. Shell cordovan is the choice of collectors who understand the value of rarity and stratified patina over time.

How do I change the strap on my Sinn 950.011?

Strap replacement requires a specific Spring Bar Tool to remove the lug pins. Start from the lower side: insert the tool into the gap between the case and the lug, press gently downward to compress the internal spring, and extract the pin. Repeat on the other side. Once the pins are removed, sliding the old strap off the lugs is straightforward. To install the new strap, position the strap holes on the pin tips, insert the pins into the lugs following the opposite sequence (upper side first, then lower) until the locking click is felt.

Which aftermarket straps are compatible with the Sinn 950.011?

All straps with a 22mm lug width are compatible with the Sinn 950.011. Milano Straps offers a curated selection of alligator, calf, NATO and rubber models specifically dimensioned for this width. Compatibility is guaranteed by compliance with ISO 1459 standard, which standardizes pin and lug dimensions. We recommend always verifying the nominal width before purchase to avoid structural strain or unwanted play.

What is the lifespan of a leather strap on the Sinn 950.011?

Leather strap lifespan varies based on material, usage and maintenance. Vegetable-tanned calf or alligator, worn daily, has an estimated lifespan of 3-5 years before showing signs of structural failure at the edges. Shell cordovan, thanks to its natural density and resistance, can reach 7-10 years. Grey or satin leather tends to wear more visibly in folding areas. Preventive maintenance (periodic application of alum oil or specific balms) extends durability. NATO straps and rubber straps, free from organic materials, have indefinite lifespan if stored away from excessive heat sources.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only