# DIMBLK1 System Variable [GstarCAD 2019](Help%20System/GSTARCAD/2019/Index.md) → [System Variables](Help%20System/GSTARCAD/2019/System%20Variables/(System%20Variables).md) → [D](Help%20System/GSTARCAD/2019/System%20Variables/D/(D).md) ## Function Description: The DIMBLK1 system variable is used to set arrowhead for the first end of extension line when the DIMSAH is on. | | | | --- | --- | | Type | Strings | | Saved in | Drawing | | Initial value | "" | Users could enter a Period "." to restore default settings. **Note:** the annotative block could not be used as customized arrow for dimensions and leaders. --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/D/DIMBLK1%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/D/DIMBLK1%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/D/DIMBLK1%20System%20Variable.md) · [GstarCAD 2020](Help%20System/GSTARCAD/2020/System%20Variables/D/DIMBLK1%20System%20Variable.md) · [GstarCAD 2021](Help%20System/GSTARCAD/2021/System%20Variables/D/DIMBLK1%20System%20Variable.md)