ASC tube trap: which's reflect or absorb side?


Hi,
Just having a few tube traps but don't know where is the starting and end point of relect or absorb side. I know that half of the trap is reflect, and the orther half is absorb but don't know where to start with.
Thanks for your help!
Tran
worldcup86
the side that is vertically stitched is the midpoint of the totally absorbtive side
Ramses' answer is my recollection with my old tube traps, which did not have the button Fmpnd mentions.
Yes, mine have a silver button. So, the side that has silver button is reflective side.
Thanks for your help!
Tran
The silver button indicates the reflective side as correctly stated by Fmpnd. However, if these are original ASC tube traps & well maintained then there should be a sticker on one of the end caps that clearly states which hemisphere is absorptive & which is reflective. FWIW.