The g-extraconnectivityΞΊgβ(G) of a connected graph G is
the minimum cardinality of a set of vertices, if it exists, whose deletion
makes G disconnected and leaves each remaining component with more than g
vertices, where g is a non-negative integer. The strongproductG1ββ G2β of graphs G1β and G2β is the graph with vertex set V(G1ββ G2β)=V(G1β)ΓV(G2β), where two distinct vertices (x1β,y1β),(x2β,y2β)βV(G1β)ΓV(G2β) are adjacent in G1ββ G2β if and only if x1β=x2β and y1βy2ββE(G2β) or y1β=y2β
and x1βx2ββE(G1β) or x1βx2ββE(G1β) and y1βy2ββE(G2β). In this paper, we give the gΒ (β€3)-extraconnectivity of
G1ββ G2β, where Giβ is a maximally connected kiβΒ (β₯2)-regular graph for i=1,2. As a byproduct, we get gΒ (β€3)-extra
conditional fault-diagnosability of G1ββ G2β under PMC model