<p class="font_8">**Zenith Defy 21 Ultraviolet Model 97.9001.9004/80.R922 Review by A.I. WatchMetrics**

### Watch Summary:
The Zenith Defy 21 Ultraviolet is a striking example of modern horological innovation, classified primarily as a Sport/Active watch due to its robust features and design. This model is powered by the El Primero 9004 automatic movement, which is renowned for its high-frequency chronograph capability, offering a power reserve of approximately 50 hours. The watch is designed for those who appreciate cutting-edge technology and bold aesthetics, featuring a vibrant ultraviolet color scheme that stands out in any setting. Its appeal lies in its combination of technical prowess and unique design, making it ideal for enthusiasts who value both performance and style.

### Overall Watch Rating: 8.5/10.0

- **Functions Metric (9.5/10.0)**
- The Zenith Defy 21 Ultraviolet excels in functionality with its high-frequency chronograph, offering precision timing. It also features a robust water resistance suitable for active use, and its lume ensures visibility in low-light conditions.

- **Movement Metric (9.3/10.0)**
- The El Primero 9004 movement is a standout feature, known for its 1/100th of a second chronograph capability. This automatic movement is a testament to Zenith's engineering excellence, providing both complexity and reliability.

- **Dials &amp; Design Metric (9.0/10.0)**
- The watch's ultraviolet dial is both innovative and visually striking, with a skeletonized design that showcases the intricate movement beneath. The use of bold colors and modern materials highlights Zenith's commitment to avant-garde design.

- **Material Metric (8.8/10.0)**
- Constructed with high-quality materials, including a titanium case and a rubber strap, the watch offers durability and comfort. The finishing is exceptional, contributing to its premium feel.

- **Complications Metric (8.5/10.0)**
- The primary complication is the high-frequency chronograph, which is both rare and highly functional. This advanced feature sets the watch apart from standard chronographs.

- **History &amp; Innovation Metric (8.3/10.0)**
- Zenith's legacy in high-frequency chronographs is well-represented in this model, showcasing the brand's historical significance and ongoing innovation in watchmaking.

- **Versatility Metric (8.0/10.0)**
- While primarily a sport watch, its unique design allows for some versatility in casual settings. However, its bold aesthetics may limit its use in formal environments.

- **Rarity Metric (7.8/10.0)**
- The Defy 21 Ultraviolet is a limited production model, enhancing its exclusivity. Its unique color scheme further adds to its rarity.

- **Brand Metric (7.5/10.0)**
- Zenith is a respected name in the watch industry, known for its pioneering work in chronograph movements. While not as universally recognized as some luxury brands, it holds a strong position among enthusiasts.

### Celebrity and Historical Figures:
Zenith watches have been favored by numerous celebrities and historical figures. Notably, Felix Baumgartner wore a Zenith watch during his record-breaking freefall from the stratosphere, highlighting the brand's association with high-performance and adventurous endeavors. While the Defy 21 Ultraviolet itself may not have specific celebrity endorsements, Zenith's reputation for innovation and quality is well-established in the horological community.</p>