diff --git a/src/descriptor.c b/src/descriptor.c
index 52186f4..b8106a6 100644
--- a/src/descriptor.c
+++ b/src/descriptor.c
@@ -287,10 +287,12 @@ static const dc_descriptor_t g_descriptors[] = {
 	/* Shearwater Predator */
 	{"Shearwater", "Predator", DC_FAMILY_SHEARWATER_PREDATOR, 2},
 	/* Shearwater Petrel */
-	{"Shearwater", "Petrel",   DC_FAMILY_SHEARWATER_PETREL, 3},
-	{"Shearwater", "Petrel 2", DC_FAMILY_SHEARWATER_PETREL, 3},
-	{"Shearwater", "Nerd",     DC_FAMILY_SHEARWATER_PETREL, 3},
-	{"Shearwater", "Perdix",   DC_FAMILY_SHEARWATER_PETREL, 3},
+	{"Shearwater", "Petrel",    DC_FAMILY_SHEARWATER_PETREL, 3},
+	{"Shearwater", "Petrel 2",  DC_FAMILY_SHEARWATER_PETREL, 3},
+	{"Shearwater", "Nerd",      DC_FAMILY_SHEARWATER_PETREL, 4},
+	{"Shearwater", "Nerd 2",    DC_FAMILY_SHEARWATER_PETREL, 4},
+	{"Shearwater", "Perdix",    DC_FAMILY_SHEARWATER_PETREL, 5},
+	{"Shearwater", "Perdix AI", DC_FAMILY_SHEARWATER_PETREL, 6},
 	/* Dive Rite NiTek Q */
 	{"Dive Rite", "NiTek Q",   DC_FAMILY_DIVERITE_NITEKQ, 0},
 	/* Citizen Hyper Aqualand */
diff --git a/src/shearwater_common.h b/src/shearwater_common.h
index b93f973..2283154 100644
--- a/src/shearwater_common.h
+++ b/src/shearwater_common.h
@@ -31,6 +31,13 @@ extern "C" {
 
 #define ID_SERIAL   0x8010
 #define ID_FIRMWARE 0x8011
+#define ID_HARDWARE 0x8050
+
+#define PREDATOR 2
+#define PETREL   3
+#define NERD     4
+#define PERDIX   5
+#define PERDIXAI 6
 
 typedef struct shearwater_common_device_t {
 	dc_device_t base;
diff --git a/src/shearwater_petrel.c b/src/shearwater_petrel.c
index 71f507e..3b60bf4 100644
--- a/src/shearwater_petrel.c
+++ b/src/shearwater_petrel.c
@@ -200,9 +200,41 @@ shearwater_petrel_device_foreach (dc_device_t *abstract, dc_dive_callback_t call
 	// Convert to a number.
 	unsigned int firmware = str2num (dc_buffer_get_data (buffer), dc_buffer_get_size (buffer), 1);
 
+	// Read the hardware type.
+	rc = shearwater_common_identifier (&device->base, buffer, ID_HARDWARE);
+	if (rc != DC_STATUS_SUCCESS) {
+		ERROR (abstract->context, "Failed to read the hardware type.");
+		dc_buffer_free (buffer);
+		dc_buffer_free (manifests);
+		return rc;
+	}
+
+	// Convert and map to the model number.
+	unsigned int hardware = array_uint_be (dc_buffer_get_data (buffer), dc_buffer_get_size (buffer));
+	unsigned int model = 0;
+	switch (hardware) {
+	case 0x0808: // Petrel 2
+	case 0x0909: // Petrel 1
+	case 0x0B0B: // Petrel 1 (newer hardware)
+		model = PETREL;
+		break;
+	case 0x0A0A: // Nerd 1
+	case 0x0E0D: // Nerd 2
+		model = NERD;
+		break;
+	case 0x0707:
+		model = PERDIX;
+		break;
+	case 0x0C0D:
+		model = PERDIXAI;
+		break;
+	default:
+		WARNING (abstract->context, "Unknown hardware type %04x.", hardware);
+	}
+
 	// Emit a device info event.
 	dc_event_devinfo_t devinfo;
-	devinfo.model = 3;
+	devinfo.model = model;
 	devinfo.firmware = firmware;
 	devinfo.serial = array_uint32_be (serial);
 	device_event_emit (abstract, DC_EVENT_DEVINFO, &devinfo);
diff --git a/src/shearwater_predator.c b/src/shearwater_predator.c
index 42a579b..3cc79f1 100644
--- a/src/shearwater_predator.c
+++ b/src/shearwater_predator.c
@@ -30,9 +30,6 @@
 
 #define ISINSTANCE(device) dc_device_isinstance((device), &shearwater_predator_device_vtable)
 
-#define PREDATOR 2
-#define PETREL   3
-
 #define SZ_BLOCK   0x80
 #define SZ_MEMORY  0x20080