Remo Weatherking Banjo Head, Clear,

Diameter 9" available in high, and medium collar.

A clear banjo head made from weather resistant Mylar

Measuring for a replacement head
To get the diameter measure the hoop the head is stretched over in 4 directions calculate the average.

The collar or crown height is the height of the head above the aluminium hoop to which the plastic head is welded. It is the height the stands up inside the tension hoop,  a low collar is 3/8", a medium collar is 7/16" and a high collar is 1/2".