This is a basically new board that was removed from a spa under warranty. Marquis had the dealer replace the board and topside control (but it was just the topside was the actual problem). I will as a matter up upgrading this board, replace the heater and high limit relays to rest the hours to zero. See below for compatibility on this board. Additionally, I offer repair service and can quote you for repair of your board. (Typically less than $140) Shipping to be a flat $20 to the lower 48. Please see my feedback and buy with confidence. 

Balboa Marquis Spa MQBP20UX-BS Circuit Board 600-6315

Used In All Signature Series Spas 2013-2019, All 2 Pump E-Series Spas 2015-2019, And All Vector Spas With Microsilk 2015-2019. Balboa Part Number 59199, Chip Number MQBP20UXR3B. Replaces 600-6307 And 600-6314.