2 convex and 2 concave 100% silicone sweat free grips. Convex right stick for enhanced precision & improved accuracy while aiming Concave left stick for grip and comfort which reduces hand and thumb fatigue. Quickly mount over existing new or worn analog thumbsticks. https://www.amazon.com/vdp/53378e3df57a4e809834a0d1e73b846d?ref=dp_vse_ibvc0 **$15.00 replacement cost.