how to chek the si or ex tranny?

i have the d15b vtec and many ppl tell me to use the si or ex traany
so
i went to the store and i found many trannys some of them have
s20 - 2356754 and other have s40-1438761 and other have no stamp
so can any one help me to chek if it for the si or ex civic ?

i just found that site http://home.cinci.rr.com/mistab0ne/tranny.html

i will chek that info and i hope help me and help you too. Hany
hanytrade@yahoo.com