Product details:

Seat located above drain; water can't be trapped and sediment can't foul seat. Non-mechanical seat-to-disc alignment will not stick or freeze. Water seal of high temperature resisting material isolates spring working parts from water during relief.Seat located above drain; water can't be trapped and sediment can't foul seat.
Non-mechanical seat-to-disc alignment will not stick or freeze.
Water seal of high temperature resisting material isolates spring working parts from water during relief.