iBPUTTER Sweet Spot QUATERNION – Balance You Can Feel from the Very First Contact
The new addition to the iBPutter Sweet Spot lineup in 2025 is Quaternion — the most premium model ever created by the brand. It carries forward the well-established design philosophy of Iván Ballesteros, where key elements converge: the central cylindrical shape, the dual-face concept, structural symmetry, the centred shaft, and the importance of precise visual alignment.

This new model builds upon the DNA of the 373G and 410G (launched in 2023) and the BX2 (launched in 2024).

Quaternion’s modern and elegant design stands out for the way it naturally rests on the ground — just like its sibling, the BX2 — instantly revealing the perfect balance of its weight and facilitating a stable setup from the very first contact with the green.

As the flagship of the iBPutter Sweet Spot series, Quaternion introduces two major innovations: it is the first model to feature a hybrid shaft made of carbon fibre and steel — engineered to reduce vibrations at impact and deliver a cleaner, more responsive feel in the hands — and it comes equipped with a premium leather grip, designed for superior comfort, tactile feedback, and timeless style.

The name “Quaternion” is inspired by the mathematical theory of quaternions, developed in the 19th century by Sir Rowan Hamilton. This theory is used to describe rotations in three-dimensional space, a concept that directly aligns with the biomechanics of the putting stroke. Furthermore, quaternions are represented by the letter H, which also visually resembles the shape of the putter head, adding symbolic depth to the name.

Crafted from high-quality 303 stainless steel and featuring milled aluminium faces, the Quaternion head weighs 395 grams, making it ideal for a firm and controlled pendulum motion. Its 3.5° loft and 70° lie angle are consistent with the optimal specifications proven in previous iBPutter Sweet Spot models.