for your GM 4l80e transmission
Direct Clutch Molded BOnded piston
the picture is a representation

Direct drum is the drum with the sprag  and sprag race

forward drum is the one where the OD planet runs on and takes the input shaft


********NOTE********
INSIDE DIAMETER IS AROUND 3.7 IN
NOT TO BE CONFUSED WITH THE FORWARD PISTON WHICH IS THE SAME EXCEPT THE INSIDE DIAMETER IS 3.37 IN AND WILL NOT FIT THE DIRECT DRUM