SAFEBOAT SWIVEL BASE MOUNT OPTIONNOTE- THIS IS ONLY THE SWIVEL BASE- NOT THE SEAT BASEYOU MAY STILL NEED THE SEAT BASE IF REPLACEING AN IN-DUTY SEATCUSTOM DRILLING AVAILABLE TO MATCH YOUR SEATS AT ADDITIOANL COSTThis optional mount kit will allow full rotation with stops at all 90 degree marksWhen installed- will add 4 inch height to overall seat so plan accordingly13x13x3Weight - 36#