oil seals needed

Hi i think ive a leak at the rear of my R380 between it and LT230 T/BOX , I know i need the o'ring on the intermediate shaft for the t/box weep , But how many seals is there between the T/box and the Gearbox
Im guessing one , but some sellers seem to be selling pairs , so is there another in that housing that joins the box and T/box ?

i dont want to pull it out only to find i dont have what i need ..... im not doing it at home so i would be up the creek if i dont finish in the day.

Do i just need the rear gearbox seal x1

@jamesmartin one for you, i believe you are the gearbox guru