diff --git a/src/main/java/net/onrc/onos/api/flowmanager/FlowBatchId.java b/src/main/java/net/onrc/onos/api/flowmanager/FlowBatchId.java
index 6b71b2f..219f779 100644
--- a/src/main/java/net/onrc/onos/api/flowmanager/FlowBatchId.java
+++ b/src/main/java/net/onrc/onos/api/flowmanager/FlowBatchId.java
@@ -2,10 +2,15 @@
 
 import java.util.Objects;
 
+import javax.annotation.concurrent.Immutable;
+
 /**
  * Represents ID for {@link FlowBatchOperation}.
+ * <p>
+ * This class is immutable.
  */
-public class FlowBatchId {
+@Immutable
+public final class FlowBatchId {
     private final long id;
 
     /**
@@ -17,7 +22,7 @@
 
     @Override
     public String toString() {
-        return Long.toString(id);
+        return "0x" + Long.toHexString(id);
     }
 
     @Override
diff --git a/src/test/java/net/onrc/onos/api/flowmanager/FlowBatchIdTest.java b/src/test/java/net/onrc/onos/api/flowmanager/FlowBatchIdTest.java
new file mode 100644
index 0000000..cfde79e
--- /dev/null
+++ b/src/test/java/net/onrc/onos/api/flowmanager/FlowBatchIdTest.java
@@ -0,0 +1,68 @@
+package net.onrc.onos.api.flowmanager;
+
+import static net.onrc.onos.core.util.ImmutableClassChecker.assertThatClassIsImmutable;
+import static org.junit.Assert.assertEquals;
+import net.onrc.onos.core.util.TestUtils;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Unit tests for {@link FlowBatchId} class.
+ */
+public class FlowBatchIdTest {
+    private FlowBatchId flowBatchId1;
+    private FlowBatchId flowBatchId2;
+    private FlowBatchId flowBatchId3;
+    private FlowBatchId flowBatchId4;
+    private FlowBatchId flowBatchId5;
+
+    @Before
+    public void setUp() {
+        flowBatchId1 = new FlowBatchId(0L);
+        flowBatchId2 = new FlowBatchId(1L);
+        flowBatchId3 = new FlowBatchId(2L);
+        flowBatchId4 = new FlowBatchId(1L);
+        flowBatchId5 = new FlowBatchId(0xABCDEFL);
+    }
+
+    /**
+     * Tests {@link FlowBatchId#FlowBatchId(long)} constructor.
+     */
+    @Test
+    public void testConstructor() {
+        assertEquals(0xABCDEFL, TestUtils.getField(flowBatchId5, "id"));
+    }
+
+    /**
+     * Tests the equality of {@link FlowBatchId} objects.
+     */
+    @Test
+    public void testEqualsAndHashCode() {
+        new EqualsTester()
+                .addEqualityGroup(flowBatchId1)
+                .addEqualityGroup(flowBatchId2, flowBatchId4)
+                .addEqualityGroup(flowBatchId3)
+                .addEqualityGroup(flowBatchId5)
+                .testEquals();
+    }
+
+    /**
+     * Tests {@link FlowBatchId#toString()} method.
+     */
+    @Test
+    public void testToString() {
+        assertEquals("0x0", flowBatchId1.toString());
+        assertEquals("0xabcdef", flowBatchId5.toString());
+    }
+
+    /**
+     * Tests if {@link FlowBatchId} is immutable.
+     */
+    @Test
+    public void testImmutable() {
+        assertThatClassIsImmutable(FlowBatchId.class);
+    }
+}