Designed for use on standard internal residential doors, including heavy 30 & 60 minute fire doors weighing up to 80kg. Smooth ball bearing action and tested to 200,000 cycles make these hinges ideal for doors with heavy domestic traffic.Smooth ball bearing action.Suitable for 30 & 60 minute fire doors.Ideal for heavy doors up to 80kg.For doors with heavy traffic – tested to 200,000 cycles” .