diff --git a/pySim/esim/saip/personalization.py b/pySim/esim/saip/personalization.py
index 3aa796a9..938bc1a0 100644
--- a/pySim/esim/saip/personalization.py
+++ b/pySim/esim/saip/personalization.py
@@ -665,69 +665,57 @@ class SmspTpScAddr(ConfigurableParameter):
 
 
 class MncLen(EnumParam):
-    """MNC length.  Sets only the MNC length field in EF.AD (Administrative Data).
-    Accepted values: integer 2 or 3, digit strings '2' or '3', or enum names 'MNC2'/'MNC3'.
-    """
+    """MNC length. Must be either 2 or 3. Sets only the MNC length field in EF-AD (Administrative Data)."""
     name = 'MNC-LEN'
-    example_input = '2'
+    value_map = { '2': 2, '3': 3 }
     default_source = param_source.ConstantSource
-
-    class Values(enum.IntEnum):
-        MNC2 = 2
-        MNC3 = 3
+    example_input = '2'
 
     @classmethod
-    def validate_val(cls, val):
-        if isinstance(val, str) and val.isdigit():
-            val = int(val)
-        return super().validate_val(val)
-
-    @classmethod
-    def _get_f_ad(cls, pe: ProfileElement):
-        if not hasattr(pe, 'files'):
-            return None
-        f_ad = pe.files.get('ef-ad', None)
-        if f_ad and f_ad.body:
-            return f_ad
-        return None
-
-    @classmethod
-    def _decode_f_ad(cls, f_ad):
-        try:
-            ef_ad_dec = EF_AD().decode_bin(f_ad.body)
-        except StreamError:
-            return None
-        if 'mnc_len' not in ef_ad_dec:
-            return None
-        return ef_ad_dec
-
-    @classmethod
-    def apply_val(cls, pes: ProfileElementSequence, val: int):
+    def apply_val(cls, pes: ProfileElementSequence, val):
+        """val must be an int: either 2 or 3"""
         for pe in pes.get_pes_for_type('usim'):
-            f_ad = cls._get_f_ad(pe)
-            if f_ad is None:
+            if not hasattr(pe, 'files'):
+                continue
+            f_ad = pe.files.get('ef-ad')
+            if not f_ad:
                 continue
             # decode existing values
-            ef_ad_dec = cls._decode_f_ad(f_ad)
-            if ef_ad_dec is None:
+            if not f_ad.body:
+                continue
+            try:
+                ef_ad = EF_AD()
+                ef_ad_dec = ef_ad.decode_bin(f_ad.body)
+            except StreamError:
+                continue
+            if 'mnc_len' not in ef_ad_dec:
                 continue
             # change mnc_len
             ef_ad_dec['mnc_len'] = val
             # re-encode into the File body
-            f_ad.body = EF_AD().encode_bin(ef_ad_dec)
+            f_ad.body = ef_ad.encode_bin(ef_ad_dec)
             pe.file2pe(f_ad)
 
     @classmethod
     def get_values_from_pes(cls, pes: ProfileElementSequence):
         for pe in pes.get_pes_for_type('usim'):
-            f_ad = cls._get_f_ad(pe)
+            if not hasattr(pe, 'files'):
+                continue
+            f_ad = pe.files.get('ef-ad', None)
             if f_ad is None:
                 continue
-            ef_ad_dec = cls._decode_f_ad(f_ad)
-            if ef_ad_dec is None:
+
+            try:
+                ef_ad = EF_AD()
+                ef_ad_dec = ef_ad.decode_bin(f_ad.body)
+            except StreamError:
                 continue
-            mnc_len = ef_ad_dec.get('mnc_len')
-            yield { cls.name: str(mnc_len) }
+
+            mnc_len = ef_ad_dec.get('mnc_len', None)
+            if mnc_len is None:
+                continue
+
+            yield { cls.name: cls.map_val_to_name(int(mnc_len)) }
 
 
 class SdKey(BinaryParam):