Number of arrangement clips in one track.
No code to comment on, but if you’re passing through a zl/list object then 256 is your default maximum list length. That’s 128 “id nn” entries.
I have added the code, but you are right i'm using ZL
Yeah so there's your answer.

But that value , is resetting, when i save the patch!
Hm, that's very odd. You could try typing it directly into the object. [zl filter @zlmaxsize 1000 id].
If you can reproduce the value not saving when you set it in the inspector you should probably file a ticket with support.
I have also observed that behaviour of zl objects listsize reset.
One needs to add @zlmaxsize argument to keep it when patch gets reopened.