diff --git a/epson_print_conf.py b/epson_print_conf.py
index 051a0aa..a0d3d2a 100644
--- a/epson_print_conf.py
+++ b/epson_print_conf.py
@@ -1699,11 +1699,23 @@ def get_serial_number(self) -> str:
             return None
         if "serial_number" not in self.parm:
             return None
-        return "".join(
-            chr(int(value or "0x3f", 16))  # "0x3f" --> "?"
-            for value in self.read_eeprom_many(
-                self.parm["serial_number"], label="serial_number")
-        )
+        if isinstance(self.parm["serial_number"], (list, tuple)):
+            left_val = None
+            for i in self.parm["serial_number"]:
+                val = "".join(
+                    chr(int(value or "0x3f", 16))  # "0x3f" --> "?"
+                    for value in self.read_eeprom_many(i, label="serial_number")
+                )
+                if left_val is not None and val != left_val:
+                    return False
+                left_val = val
+            return left_val
+        else:
+            return "".join(
+                chr(int(value or "0x3f", 16))  # "0x3f" --> "?"
+                for value in self.read_eeprom_many(
+                    self.parm["serial_number"], label="serial_number")
+            )
 
     def get_printer_brand(self) -> str:
         """Return the producer name of the printer ("EPSON")."""
@@ -2076,11 +2088,30 @@ def update_parameter(
             or not self.parm[parameter]
             or not value_list
             or not len(value_list)
-            or len(self.parm[parameter]) != len(value_list)
+            or (
+                isinstance(self.parm[parameter], (list, tuple))
+                and not all(
+                    len(sublist) == len(value_list)
+                    for sublist in self.parm[parameter]
+                )
+            )
+            or (
+                not isinstance(self.parm[parameter], (list, tuple))
+                and len(self.parm[parameter]) != len(value_list)
+            )
         ):
             return None
         if dry_run:
             return True
+        if isinstance(self.parm[parameter], (list, tuple)):
+            for i in self.parm[parameter]:
+                for oid, value in zip(i, value_list):
+                    if not self.write_eeprom(
+                        oid, value, label="update_" + parameter
+                    ):
+                        return False
+                    return True
+            return False
         for oid, value in zip(self.parm[parameter], value_list):
             if not self.write_eeprom(oid, value, label="update_" + parameter):
                 return False
diff --git a/ui.py b/ui.py
index 940e053..7ca09e1 100644
--- a/ui.py
+++ b/ui.py
@@ -32,7 +32,7 @@
 from find_printers import PrinterScanner
 
 
-VERSION = "5.0"
+VERSION = "5.1"
 
 NO_CONF_ERROR = (
     "[ERROR] Please select a printer model and a valid IP address,"
@@ -1318,6 +1318,14 @@ def get_ser_number(self, cursor=True):
             self.config(cursor="")
             self.update_idletasks()
             return
+        if ser_num is False:
+            self.status_text.insert(
+                tk.END,
+                f"[ERROR]: Improper values in printer serial number.\n",
+            )
+            self.config(cursor="")
+            self.update_idletasks()
+            return
         if not ser_num or "?" in ser_num:
             self.status_text.insert(
                 tk.END,
@@ -1588,19 +1596,22 @@ def set_ser_number(self, cursor=True):
             self.config(cursor="")
             self.update_idletasks()
             return
-        try:
-            if not self.get_current_eeprom_values(
-                self.printer.parm["serial_number"],
-                "Printer Serial Number"
-            ):
+        pr_ser_num = self.printer.parm["serial_number"]
+        if isinstance(pr_ser_num, (list, tuple)):
+            list_ser_num = pr_ser_num
+        else:
+            list_ser_num = [pr_ser_num]
+        for i in list_ser_num:
+            try:
+                if not self.get_current_eeprom_values(i, "Printer Serial Number"):
+                    self.config(cursor="")
+                    self.update_idletasks()
+                    return
+            except Exception as e:
+                self.handle_printer_error(e)
                 self.config(cursor="")
                 self.update_idletasks()
                 return
-        except Exception as e:
-            self.handle_printer_error(e)
-            self.config(cursor="")
-            self.update_idletasks()
-            return
         self.status_text.insert(
             tk.END,
             f"[INFO] Set Printer Serial Number: {self.ser_num_var.get()}.\n"
@@ -2146,29 +2157,37 @@ def run_detection():
                     tk.END,
                     f"[ERROR] Cannot detect the serial number.\n"
                 )
-            elif len(matches) != 1:
-                self.status_text.insert(
-                    tk.END,
-                    "[ERROR] More than one pattern appears to be"
-                    " a serial number:\n"
-                )
+            left_ser_num = None
+            for match in matches:
+                tmp_ser_num = match.group()
+                if left_ser_num is not None and tmp_ser_num != left_ser_num:
+                    self.status_text.insert(
+                        tk.END,
+                        "[ERROR] More than one pattern appears to be"
+                        " a serial number with different values:\n"
+                    )
+                    for match in matches:
+                        self.status_text.insert(
+                            tk.END,
+                            f'[ERROR] - found pattern "{match.group()}"'
+                            f" at address {match.start()}\n"
+                        )
+                    left_ser_num = None
+                    break
+                left_ser_num = tmp_ser_num
+            if left_ser_num:
                 for match in matches:
+                    serial_number = match.group()
+                    serial_number_address = match.start()
+                    serial_number_range = range(
+                        serial_number_address,
+                        serial_number_address + len_ser_num
+                    )
                     self.status_text.insert(
                         tk.END,
-                        f'[ERROR] - found pattern "{match.group()}"'
-                        f" at address {match.start()}\n"
+                        f'[INFO] Detected serial number "{serial_number}"'
+                        f" at address {serial_number_address}.\n"
                     )
-            else:
-                serial_number = matches[0].group()
-                serial_number_address = matches[0].start()
-                serial_number_range = range(
-                    serial_number_address, serial_number_address + len_ser_num
-                )
-                self.status_text.insert(
-                    tk.END,
-                    f'[INFO] Detected serial number "{serial_number}"'
-                    f" at address {serial_number_address}.\n"
-                )
                 last_ser_num_addr = serial_number_address + len_ser_num - 1
                 last_ser_num_value = int(hex_bytes[last_ser_num_addr], 16)
                 self.status_text.insert(