Strap for Senator Perpetual Calendar Stainless Steel Black / Rubber / Folding

The lug width of the Senator 100-02-25-12-04 is 20 millimetres. This dimension is proportional to the 42mm case and represents the official Glashütte specification. It is measured perpendicularly between the two spring bar pins, from the upper to the lower attachment point. Any aftermarket strap must respect this exact dimension to ensure correct positioning and mechanical stability.

For the Senator 100-02-25-12-04, an alligator strap of quality construction is recommended, preferably with vegetable tanning, to maintain aesthetic coherence with the watch's formal character. Alligator offers a regular texture, a patina that develops naturally and constructive elegance compatible with Saxonian movement finishing. Alternatively, vegetable-tanned calf leather or a technical rubber strap provide versatility whilst maintaining balanced visual proportions. NATO straps are technically compatible but tend to visually overweight the design.

The strap is changed by removing the spring bar that connects the strap to the case. Use a dedicated spring bar removal tool to compress the pin and disengage the strap from the lugs. Position the tool parallel to the lug, apply controlled pressure and extract the strap. The reverse procedure applies the new strap: insert the pin into the upper seat, compress lightly with the removal tool and allow the pin to snap into the lower seat. This method preserves the integrity of the case and lugs.

Yes, the Senator 100-02-25-12-04 is fully compatible with high-quality aftermarket straps, provided they strictly respect the 20-millimetre lug width. Straps in alligator, calf leather, shell cordovan, technical rubber or NATO of the correct width can be fitted without modification. It is essential to verify that the strap has regularly spaced passage holes and that the spring bar pins are stainless steel of quality to prevent corrosion. Milano Straps offers a complete selection of tested and compatible 20mm straps.

A high-quality leather strap—alligator, calf, shell cordovan—fitted to the Senator 100-02-25-12-04 maintains optimal performance for 3-5 years of daily use, provided it receives appropriate maintenance. Longevity depends on environmental factors: sun exposure, humidity, usage frequency and perspiration accelerate ageing. Vegetable tanning develops a desirable patina within the first 6-12 months, whilst synthetic resin straps have more predictable degradation timelines. A technical rubber strap offers superior durability (7-10 years) with less aesthetic complexity. Periodic replacement is part of standard aftermarket strap management.