diff --git a/cg_lims/EPPs/udf/set/constants.py b/cg_lims/EPPs/udf/set/constants.py
new file mode 100644
index 00000000..54e91179
--- /dev/null
+++ b/cg_lims/EPPs/udf/set/constants.py
@@ -0,0 +1,17 @@
+from cg_lims.enums import IntEnum
+
+
+class DefaultReadLength(IntEnum):
+    """Default read length most usually used by each flow cell type."""
+
+    FLOW_CELL_10B: int = 151
+    FLOW_CELL_25B: int = 151
+    FLOW_CELL_15B: int = 51
+
+
+class DefaultIndexLength(IntEnum):
+    """Default index length most usually used by each flow cell type."""
+
+    FLOW_CELL_10B: int = 10
+    FLOW_CELL_25B: int = 10
+    FLOW_CELL_15B: int = 8