The difference between WA and WB ecu

[Juan_18]

Hello friend this is my cuestion there are any difference between this ECU


http://www.silviastuff.com/images/sr20deecu.jpg

and this one


http://image.nengun.com/used/original/nengun-98520-00-nissan-silvia_s14_se20de_genuine_ecu_first_semester.jpg