Precision-engineered for AEG hop-up systems, these HNBR pressure nubs deliver consistent bucking contact and uniform BB engagement during firing. The advanced elastomer compound resists oils, grease, and temperature extremes while maintaining mechanical integrity through extended use. Superior pressure distribution across the bucking surface generates stable backspin and refined trajectory control shot after shot. This two-piece set provides reliable performance and convenient replacement options for maintaining peak hop-up function.