Bung Adapter Adapter Material Polypropylene For Container Size 15 gal 30 gal 55 gal For Container Type Drum Bung Connection Dia I D =2 in O D= 2.73 in Adapter Connection Type BSP Wetted Materials Polypropylene For Use With Converts 2.73 In Coarse Threads on Plastic Drums to 2 In Fine Threads Allowing Most Pumps with 2 In Fine Threads To Be Used With Plastic Drums