AutoRebar lets you draw dynamic Rebars as if they were polylines. You can stretch them, bend them, cut them, change the diameter, the scale; dynamic Rebars react like real steel bars. 

Insert dynamic Marks linked to Rebars; a Mark instantly reacts to any change you make to the linked Rebar
Specify the Rebar spacing for a Mark, and link the Mark to any standard AutoCAD® Dimension to specify its extension field and calculate the total number of Rebars in that position; when you stretch linked Dimensions, Marks, Calls and the total number of Rebars are kept up to date.