@dale, please have a look at below attached script. I’ve tried to create the leader using RhinoCommon and found that i cannot set LeaderHasLanding and LeaderLandingLength before adding the leader object to the document. There seems to be something i do not get while setting both properties or they are forced to be read from the current dimstyle. (Note, the script is supposed to work on named objects picked in a layout/detail view).