Fit is measured in millimetres but felt in balance.

A strap must match the lug width precisely. Any deviation compromises both security and aesthetics. Thickness should complement the case, not overpower it. Slim cases demand restraint. Tool watches tolerate more presence.

Length matters. A strap should close near the centre holes, leaving a clean tail with minimal excess. Too long appears careless. Too short feels forced.

Proportion is quiet. When correct, it goes unnoticed.
When wrong, it distracts immediately.

The best strap disappears allowing the watch to lead.