A comparison image from The Players Championship places Jimmy Walker's prototype irons beside his current Titleist MB 714 8-iron. The prototype looks more rounded, and its hosel carries a "716" marking. That could connect the club to Titleist's 2016 iron launch, but it does not confirm a retail model or release.
What the comparison shows
Catalog listings confirm that Titleist sold 716 AP1 and CB iron models, but they do not establish that Walker's photographed prototype became a retail MB model.
Tour equipment sightings can show different kinds of changes. This grip-change report tracked a putting adjustment. Walker's photos, by contrast, put the focus on an iron prototype.
A prototype is not a confirmed launch
The available independent materials do not verify the prototype's head dimensions, loft, offset, metal composition, model number, production status or manufacturing date.
Catalog records show why the marking alone cannot settle the question. Titleist 716 listings include AP1 and CB models. Play It Again Sports also lists 716 AP1 and CB sets. Neither catalog establishes that a retail MB version existed or connects those clubs to Walker's prototype.
The available catalog and reference materials contain no independent official comment from Titleist about the prototype's purpose. They also contain no comment from Walker or the PGA Tour on its specifications or retail future.
