diff --git a/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/Cp21xxSerialDriver.java b/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/Cp21xxSerialDriver.java
index 27ac350..4589e84 100644
--- a/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/Cp21xxSerialDriver.java
+++ b/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/Cp21xxSerialDriver.java
@@ -112,10 +112,6 @@ public class Cp21xxSerialDriver implements UsbSerialDriver {
         private static final int RTS_ENABLE = 0x202;
         private static final int RTS_DISABLE = 0x200;
 
-        private UsbEndpoint mReadEndpoint;
-        private UsbEndpoint mWriteEndpoint;
-        private UsbRequest mUsbRequest;
-
         private boolean dtr = false;
         private boolean rts = false;