JT Steel Sprockets are the OEM quality choice, manufactured using only the finest grade of C49 high carbon steel for the rear sprockets, and SCM420 chromoly steel alloy for the front sprockets.
Fits:

40 Teeth
Suzuki Off Road
TM400 R,J,K,L,M 71-75

Suzuki Road
TS250 B,C,N,T,X 77-81
TS250 A,B,C 75-79
TS250 ERN,T 80-83
TS400 J,K,L,M,A,B 72-77