Thank you for viewing. This is a Yokomo gear differential. It has resin bevel gears and aluminum joint cups. 10000 weight oil is installed. A new protector is also included. It was installed on an RDX and only run for about 5 minutes, so the condition is good, but it is a used item, so please understand and purchase only if you agree. Please refrain from purchasing if you are overly concerned about details.