September 3, 2026 – Mizuno has announced the launch of the Mizuno Pro S-4, the newest addition to its growing Signature Series iron lineup and the most forgiving model in the series to date. Developed for players who demand the refined look, precision, and forged feel of a Mizuno Pro iron, the S-4 introduces a higher-launching player’s cavity back profile designed to offer greater forgiveness and stability throughout the set.

The Signature Series was created to serve the evolving needs of the game’s best players, recognising that no single iron profile can satisfy the wide range of preferences found at the highest level. The Mizuno Pro S-1offers the purity, control, and direct feedback of a muscle back, while the S-3 delivers the versatility of a tour-driven player’s cavity. The new S-4 expands that range further, combining the look and control of a player’s iron with added launch, stability, and confidence.

At the heart of the S-4 is a more forgiving cavity back design achieved through increased offset, a wider sole, a lower sweet spot height, and a deeper centre of gravity. These elements work together to help players launch the ball more easily, improve stability on off-centre strikes, and create more consistent performance throughout the set.

The S-4 also incorporates a progressive design philosophy that carefully manages offset flow and topline thickness from the longer irons through to the scoring clubs. Longer irons feature added confidence at address and design elements that promote easier launch, while the scoring irons transition into a more compact profile to preserve the precision and control expected from a Mizuno Pro iron.

This progressive approach allows each iron to perform according to its role within the set, blending added assistance in the longer clubs with greater precision as golfers move into their scoring irons.

Further enhancing playability is Mizuno’s Triple-Cut Sole. Engineered to improve turf interaction, the sole geometry allows the club to move efficiently through a variety of conditions while helping maintain speed and consistency through impact. The result is cleaner contact and greater control from a wide range of lies.

As with every iron in the Signature Series, the S-4 is built around Mizuno’s renowned forging expertise. Each head is forged from a single billet of 1025E Pure Select Mild Carbon Steel using Mizuno’s patented Grain Flow Forged HD process, delivering the unmistakably soft, responsive feel that has defined Mizuno irons for generations. A copper underlay further refines vibration characteristics and feedback at impact.

Mizuno’s Harmonic Impact Technology sound tuning complements the forging process by carefully managing vibration and acoustics at impact. Together, these technologies create the solid sound and responsive feedback preferred by accomplished players, preserving the precise feel expected from a Mizuno Pro iron.

Visually, the S-4 remains true to the Signature Series identity, with a redesigned cavity muscle structure featuring softer, flowing geometry throughout the back of the iron. The refined shaping strategically distributes mass to enhance stability and forgiveness, while a progressive topline, flowing offset progression, and premium finish preserve the clean, compact appearance that defines the Mizuno Pro aesthetic.

With the addition of the Mizuno Pro S-4, the Signature Series now offers its broadest performance range yet. From the shot-making purity of the S-1 to the tour-proven versatility of the S-3 and the added forgiveness of the S-4, the series continues to reflect Mizuno’s commitment to creating irons for the diverse demands of accomplished players.

RRP: 265€ per club.