diff --git a/DiscImageChef.Helpers/Extents/ExtentsByte.cs b/DiscImageChef.Helpers/Extents/ExtentsByte.cs
index 2e6717a9..a4ac1914 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsByte.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsByte.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(byte item, out byte start)
+        {
+            start = 0;
+            foreach(Tuple<byte, byte> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsInt.cs b/DiscImageChef.Helpers/Extents/ExtentsInt.cs
index 91604f11..2b9d46fb 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsInt.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsInt.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(int item, out int start)
+        {
+            start = 0;
+            foreach(Tuple<int, int> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsLong.cs b/DiscImageChef.Helpers/Extents/ExtentsLong.cs
index 11e1c7f0..eae4ca61 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsLong.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsLong.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(long item, out long start)
+        {
+            start = 0;
+            foreach(Tuple<long, long> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsSByte.cs b/DiscImageChef.Helpers/Extents/ExtentsSByte.cs
index bfc07ac9..25af736e 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsSByte.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsSByte.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(sbyte item, out sbyte start)
+        {
+            start = 0;
+            foreach(Tuple<sbyte, sbyte> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsShort.cs b/DiscImageChef.Helpers/Extents/ExtentsShort.cs
index f508ace8..079c3464 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsShort.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsShort.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(short item, out short start)
+        {
+            start = 0;
+            foreach(Tuple<short, short> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsUInt.cs b/DiscImageChef.Helpers/Extents/ExtentsUInt.cs
index 3d0988da..bd24b6db 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsUInt.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsUInt.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(uint item, out uint start)
+        {
+            start = 0;
+            foreach(Tuple<uint, uint> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsULong.cs b/DiscImageChef.Helpers/Extents/ExtentsULong.cs
index c9f45706..fcb7a40b 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsULong.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsULong.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(ulong item, out ulong start)
+        {
+            start = 0;
+            foreach(Tuple<ulong, ulong> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }
diff --git a/DiscImageChef.Helpers/Extents/ExtentsUShort.cs b/DiscImageChef.Helpers/Extents/ExtentsUShort.cs
index 9f7da19b..3e019e2a 100644
--- a/DiscImageChef.Helpers/Extents/ExtentsUShort.cs
+++ b/DiscImageChef.Helpers/Extents/ExtentsUShort.cs
@@ -201,5 +201,19 @@ namespace Extents
         {
             return backend.ToArray();
         }
+
+        public bool GetStart(ushort item, out ushort start)
+        {
+            start = 0;
+            foreach(Tuple<ushort, ushort> extent in backend)
+            {
+                if(item >= extent.Item1 && item <= extent.Item2)
+                {
+                    start = extent.Item1;
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 }