diff --git a/src/descriptor.c b/src/descriptor.c
index 5a04025..d35c690 100644
--- a/src/descriptor.c
+++ b/src/descriptor.c
@@ -150,7 +150,9 @@ static const dc_descriptor_t g_descriptors[] = {
 	{"Mares", "Icon HD",           DC_FAMILY_MARES_ICONHD , 0x14},
 	{"Mares", "Icon HD Net Ready", DC_FAMILY_MARES_ICONHD , 0x15},
 	/* Heinrichs Weikamp */
-	{"Heinrichs Weikamp", "OSTC", DC_FAMILY_HW_OSTC, 0},
+	{"Heinrichs Weikamp", "OSTC",     DC_FAMILY_HW_OSTC, 0},
+	{"Heinrichs Weikamp", "OSTC Mk2", DC_FAMILY_HW_OSTC, 1},
+	{"Heinrichs Weikamp", "OSTC 2N",  DC_FAMILY_HW_OSTC, 2},
 	{"Heinrichs Weikamp", "Frog", DC_FAMILY_HW_FROG, 0},
 	/* Cressi Edy */
 	{"Cressi", "Edy", DC_FAMILY_CRESSI_EDY, 0},
diff --git a/src/hw_ostc.c b/src/hw_ostc.c
index a2eabf7..c500858 100644
--- a/src/hw_ostc.c
+++ b/src/hw_ostc.c
@@ -323,9 +323,14 @@ hw_ostc_device_foreach (dc_device_t *abstract, dc_dive_callback_t callback, void
 	// Emit a device info event.
 	unsigned char *data = dc_buffer_get_data (buffer);
 	dc_event_devinfo_t devinfo;
-	devinfo.model = 0;
 	devinfo.firmware = array_uint16_be (data + 264);
 	devinfo.serial = array_uint16_le (data + 6);
+	if (devinfo.serial > 2048)
+		devinfo.model = 2; // OSTC 2N
+	else if (devinfo.serial > 300)
+		devinfo.model = 1; // OSTC Mk2
+	else
+		devinfo.model = 0; // OSTC
 	device_event_emit (abstract, DC_EVENT_DEVINFO, &devinfo);
 
 	rc = hw_ostc_extract_dives (abstract, dc_buffer_get_data (buffer),