“A compact slot-back mid-mallet that also comes in an armlock build. More stable than a blade with a hint of toe hang, good for a very slight arc or a straighter stroke. One of Bettinardi's most versatile shapes.”

The BB28 is a compact slot-back mid-mallet built around a full-flange, near-face-balanced head, and it doubles as one of Bettinardi's dedicated armlock platforms — the Armlock version has 5 degrees of loft milled directly into the face to compensate for the forward-leaned shaft/forearm setup that armlock putting requires. Milled from 303 stainless steel with Bettinardi's Aggressive Flymill face, it launched into the armlock boom of the late 2010s (Bryson DeChambeau, Matt Kuchar and others popularizing the anchored-to-forearm technique) as a purpose-built option rather than a standard putter with a longer shaft bolted on.

It rode a real equipment-trend wave — armlock putting's rise on Tour and in retail — as one of Bettinardi's purpose-engineered armlock heads rather than a generic long-shaft conversion, which gave it a genuine functional niche; it has not become a broadly discussed or scarce collector piece outside that use case.

Golfers moving to armlock putting who want loft built into the face rather than added at setup, or straight/slight-arc stroke players who want more stability than a blade without going to a full high-MOI mallet. Traditional-stroke blade players should stay with a BB1/BB0-type shape.

• The Armlock BB28 has 5 degrees of loft milled into the face, built specifically to counteract the forward shaft lean of armlock setups.
• It is built with a full-flange design for greater perimeter weighting and higher MOI than a standard blade or mid-mallet.
• Constructed from 303 stainless steel, the same alloy Bettinardi cites as preferred by its Tour staff for feel.
• The BB28 shape has persisted in Bettinardi's catalog long enough to be reissued as the 'BB28 Slotback' and in Studio B Reserve limited finishes years after its 2018 debut.

It launched alongside a wave of armlock-specific offerings across the industry (Odyssey, Ping, SeeMore) as manufacturers responded to Bryson DeChambeau's and other pros' visible use of the technique in 2017-2019; Bettinardi's approach of milling loft into the face rather than just lengthening a standard head was a direct answer to that trend.

Private-party prices commonly land around $180-$300; 2nd Swing has listed used BB28 Slotback stock around $168-$345 depending on condition and configuration (standard vs. Armlock length), which roughly brackets the realistic secondary-market range.