Drum Pump Adaptor Male 55mm 
Pump adaptors come in a wide variety of thread types and sizes, allowing connection to almost any drum. Most pumps are supplied with the adaptors most commonly required for the appropriate size pump. Other adaptors, or replacement adaptors, are supplied to order. For 'male' adaptors the dimension is the overall outside diameter of the thread portion of the container bung. For caps ('female') the dimension is the clear internal diameter of the container cap thread.