This is a 6" round O.D. by 4.75" I.D. gasket with 6 holes used between the combustion blower and housing on pellet stoves with the 6" 'quick change' style motor. Good idea to change these when doing a thorough cleaning especially if there was a bit of vibration from the motor. Please note the gasket you receive will have (6) slots rather than holes to fit many different makes and models.