BBQ Grill Replacement Part The Beefeater Black Knob 55mm (6.5mm Insert) is a well adaptive knob which is designed to promote high compatibility for use with the Beefeater barbecue. This knob features a black color appearance which makes it suitable for matching perfectly with any gas barbecue it is placed on. It is 55mm in size and features a 6.5mm insert. This barbecue knob is designed to provide visual identification of when the barbecue is on and in use. It is easy to install and easy to use for added convenience.