diff --git a/phoenix/src/main/java/com/mmorrell/phoenix/model/FIFOOrderId.java b/phoenix/src/main/java/com/mmorrell/phoenix/model/FIFOOrderId.java
new file mode 100644
index 0000000..1916649
--- /dev/null
+++ b/phoenix/src/main/java/com/mmorrell/phoenix/model/FIFOOrderId.java
@@ -0,0 +1,14 @@
+package com.mmorrell.phoenix.model;
+
+import lombok.Builder;
+import lombok.Data;
+
+@Data
+@Builder
+public class FIFOOrderId {
+
+    public static final int FIFO_ORDER_ID_SIZE = 16;
+    private long priceInTicks;
+    private long orderSequenceNumber;
+
+}
diff --git a/phoenix/src/main/java/com/mmorrell/phoenix/model/FIFORestingOrder.java b/phoenix/src/main/java/com/mmorrell/phoenix/model/FIFORestingOrder.java
new file mode 100644
index 0000000..be44e83
--- /dev/null
+++ b/phoenix/src/main/java/com/mmorrell/phoenix/model/FIFORestingOrder.java
@@ -0,0 +1,16 @@
+package com.mmorrell.phoenix.model;
+
+import lombok.Builder;
+import lombok.Data;
+
+@Data
+@Builder
+public class FIFORestingOrder {
+
+    public static final int FIFO_RESTING_ORDER_SIZE = 32;
+    private long traderIndex;
+    private long numBaseLots;
+
+    // 16 bytes of padding
+
+}