Rockcentrics were one of Mark Vallance's last creations and are another part of his huge legacy and testimony to his foresight about climbing gear.
In hindsight it seems obvious with Wild Country being the company that replaced flat-sided nuts with curved Rocks that the logical step to do the same with bigger nuts and it is sometimes these simple steps forward that make the biggest impact and curving the sides of a 'hex' was a simple step that had a dramatic effect. A best seller from day one, the Rockcentric's success can be attributed to the combination of: curved sides seating much more effectively than the flat sided nuts, the all-around ease of placement or removal and the light weight compared to the original Hex.
As people replaced these old Hexes on their racks, they noticed the other big plus point for the Rockcentric was its versatility, in that one nut can provide four placement modes. And as of two of these were 'camming style placements', they made an effective starter tool for those who couldn't afford or weren't confident using cams. As well as this, the fact that Rockcentrics were on pre-sewn 12mm Dynnema meant confidence in their rating of 12kn compared to threading up Hexes with rope of indeterminable strength. Dyneema also meant flexibility, it would go over edges better and generally didn't need lengthening. This allowed a single krab to be used rather than a QD reducing the overall weight of the climber's rack.
And there isn't really a rack which Rockcentrics don't suit, from the eager beginner, to the gnarliest winter freak, to the trad climber wanting to push the boat out with less weight on the their rack. Overall, Rockcentrics are easy to select, easy to place, and their place amongst the best selling kit of all time is testament to their enduring usefulness.