diff --git a/src/calibre/devices/cybookg3/driver.py b/src/calibre/devices/cybookg3/driver.py
index ea6376df0d..4ab6dc297b 100644
--- a/src/calibre/devices/cybookg3/driver.py
+++ b/src/calibre/devices/cybookg3/driver.py
@@ -9,6 +9,7 @@ from itertools import cycle
 
 from calibre.devices.usbms.driver import USBMS
 import calibre.devices.cybookg3.t2b as t2b
+from calibre.devices.errors import FreeSpaceError
 
 class CYBOOKG3(USBMS):
     # Ordered list of supported formats
diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index f5c176bcdb..d85fdef29a 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -3,10 +3,10 @@ __copyright__ = '2009, John Schember <john at nachtimwald.com>'
 '''
 Generic device driver. This is not a complete stand alone driver. It is
 intended to be subclassed with the relevant parts implemented for a particular
-device. This class handles devive detection.
+device. This class handles device detection.
 '''
 
-import os, subprocess, time
+import os, subprocess, time, re
 
 from calibre.devices.interface import Device as _Device
 from calibre.devices.errors import DeviceError
diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index 75f04219e7..eb02408aef 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -11,9 +11,23 @@ from itertools import cycle
 
 from calibre.devices.usbms.device import Device
 from calibre.devices.usbms.books import BookList, Book
-from calibre.devices.errors import FreeSpaceError
+from calibre.devices.errors import FreeSpaceError, PathError
 from calibre.devices.mime import MIME_MAP
 
+class File(object):
+    def __init__(self, path):
+        stats = os.stat(path)
+        self.is_dir = os.path.isdir(path)
+        self.is_readonly = not os.access(path, os.W_OK)
+        self.ctime = stats.st_ctime
+        self.wtime = stats.st_mtime
+        self.size  = stats.st_size
+        if path.endswith(os.sep):
+            path = path[:-1]
+        self.path = path
+        self.name = os.path.basename(path)
+
+
 class USBMS(Device):
     FORMATS = []
     EBOOK_DIR_MAIN = ''