Key Features:Heavy duty Gibraltar 9000 series hardwareFits throne tops with 7/8″ (2.22 cm) tube mountDouble Braced Throne BaseHeight adjustable 51 cm – 71 cmWith Memory Lock for height adjustmentGibraltar Throne Separates offer Nothing But Options. All seats fit onto a 7/8″ diameter shaft. All seats and base are covered under Gibraltar’s 3-year warranty.