diff --git a/converter/sun_usb/Makefile b/converter/sun_usb/Makefile
index 4c79a8d2..c6e8390c 100644
--- a/converter/sun_usb/Makefile
+++ b/converter/sun_usb/Makefile
@@ -11,6 +11,7 @@ TARGET_DIR = .
 SRC =	keymap.c \
 	matrix.c \
 	led.c \
+	command_extra.c \
 	protocol/serial_soft.c
 
 CONFIG_H = config.h
diff --git a/converter/sun_usb/command_extra.c b/converter/sun_usb/command_extra.c
new file mode 100644
index 00000000..50389467
--- /dev/null
+++ b/converter/sun_usb/command_extra.c
@@ -0,0 +1,43 @@
+#include "stdbool.h"
+#include "stdint.h"
+#include "keycode.h"
+#include "serial.h"
+#include "print.h"
+#include "command.h"
+
+bool command_extra(uint8_t code)
+{
+    switch (code) {
+        case KC_H:
+        case KC_SLASH: /* ? */
+            print("\n\n----- Sun converter Help -----\n");
+            print("UP:	Bell On\n");
+            print("DOWN:	Bell Off\n");
+            print("LEFT:	Click On\n");
+            print("RIGHT:	Click Off\n");
+            return false;
+        case KC_UP:
+            print("Bell On\n");
+            serial_send(0x02);
+            break;
+        case KC_DOWN:
+            print("Bell Off\n");
+            serial_send(0x03);
+            break;
+        case KC_LEFT:
+            print("Click On\n");
+            serial_send(0x0A);
+            break;
+        case KC_RIGHT:
+            print("Click Off\n");
+            serial_send(0x0B);
+            break;
+        case KC_NUMLOCK:
+            print("layout\n");
+            serial_send(0x0F);
+            break;
+        default:
+            return false;
+    }
+    return true;
+}