The TaylorMade Rossa Monza Spider putter design and appearance are so strikingly different as TaylorMade engineers focused on giving the Monza Spider increased stability and forgiveness. To increase the TaylorMade Rossa Monza Spider's forgiveness, TaylorMade engineers had to increase its moment of inertia (MOI). They found three key ways to accomplish that by using a steel wire-frame head construction similar to that used in the Monza Corza, which allows them to position increased weight at the perimeter, adding stability on miss-hits that helps the putter head resist twisting when impact is made toward the heel or toe. Also a light and strong aluminium core that allows more weight to be positioned on the perimeter, increasing MOI and the TaylorMade Rossa Monza Spider's "wings," into which Movable Weight Technology (MWT) cartridges are inserted, allow substantial weight to be concentrated in areas far from the face, helping to move the centre of gravity (CG) rearward, which increases MOI and stability. Of course, another benefit of the Monza Spider's MWT is that it also gives players the option to customize its feel by changing the weights to make the putter head heavier or lighter and/or to change the putter's balance.

Dynamic testing of the TaylorMade Rossa Monza Spider's performance on miss-hits indicates that, compared to miss-hit performance of competitive high-MOI putters, Monza Spider delivers dramatically better results when impact is made away from the centre of the clubface toward the heel or toe. Specifically, Monza Spider's high MOI helps it to deliver extremely consistent distance results on off-centre hits, so that instead of coming up short, oftentimes the ball reaches the hole. As for great roll, Monza Spider has the advantage of Rossa's renowned and tour-proven AGSI+ (Anti-skid Groove System Insert) Technology. AGSI+ features 14 polymer-filled grooves in the face that "hold" the ball briefly at impact to promote forward spin for a smoother roll and more accurate results. The AGSI+ insert, in concert with the putter head’s extremely high MOI, also delivers superior consistency in forward roll on off-centre hits, something not shown in tests of other popular putters. On the crown, Monza Spider incorporates an optically friendly alignment aid that was created with input from tour professionals. The aid is specially designed to work with the geometry of the putter head and the ball to make it simple to aim the putter face accurately. That, in turn, makes it easier to get the ball started on the intended line.

In summary, the convergence of Monza Spider's unique design geometry, advanced multi-material construction, Movable Weight Technology and AGSI+ Technology have produced something extraordinary. TaylorMade testing indicates that Monza Spider's MOI rating is 35% higher than the tour-proven Monza Corza meaning extraordinary stability and energy transfer on heel and toe hits for dramatically improved results. Its AGSI+ Technology promotes forward spin on centre hits, and works in conjunction with its advanced geometry and weighting to dramatically diminish the production of backspin on heel and toe hits. It all allows Monza Spider to deliver a level of performance across the clubface that isn't marginally better than other putters, but dramatically better.