diff --git a/chunk/file.go b/chunk/file.go
new file mode 100644
index 0000000..ddb43f6
--- /dev/null
+++ b/chunk/file.go
@@ -0,0 +1,49 @@
+package chunk
+
+import (
+	"io"
+	"os"
+
+	"pcloud/api"
+)
+
+type ReadOnlyFileChunk struct {
+	f      *os.File
+	offset int
+	size   int
+}
+
+func NewReadOnlyFileChunk(f *os.File, offset, size int) Chunk {
+	return &ReadOnlyFileChunk{f, offset, size}
+}
+
+func (c *ReadOnlyFileChunk) Stats() (ChunkInfo, error) {
+	return ChunkInfo{
+		Status:    api.ChunkStatus_READY,
+		Size:      c.size,
+		Committed: c.size}, nil
+}
+
+func (c *ReadOnlyFileChunk) ReaderAt() io.ReaderAt {
+	return &fileReader{c.f}
+}
+
+func (c *ReadOnlyFileChunk) WriterAt() io.WriterAt {
+	return &fileWriter{c.f}
+}
+
+type fileReader struct {
+	f *os.File
+}
+
+func (f *fileReader) ReadAt(b []byte, offset int64) (int, error) {
+	return f.f.ReadAt(b, offset)
+}
+
+type fileWriter struct {
+	f *os.File
+}
+
+func (f *fileWriter) WriteAt(b []byte, offset int64) (int, error) {
+	return f.f.WriteAt(b, offset)
+}