Basically, a higher MOI (resistance to change in rotation) in a club allows you to be more accurate by being more forgiving in your swing.
On top of this radical MOI, the SUMO also boasts a 460 cc club head volume that maxes out the USGA's restriction. The USGA also has a limit of 5900 g cm2 for a club's MOI, making the SUMO an extreme driver choice.
Also known as the XQ Muto 460 Ti, SUMO stands for Super Moment of Inertia Squared in reference to its huge MOI. This club has a composite crown instead of the traditional titanium to save weight.
The SUMO promises distances, forgiveness, and accuracy for around $400, and is available with several loft choices, and swing weights. There is also a women's model available.