Stern dual-opto out hole trough up kicker receiver board with grommets. Symptoms of defective opto boards include multiple balls being served and continuously kicking ball shooters. Can be substituted for 520-5174-00. Can be used with Stern Avatar, Avatar Limited Edition, Big Buck Hunter, Family Guy, Lord Of The Rings, Pirates Of The Caribbean, Rolling Stones, and Tron as well as Sega Godzilla.