The quartz banger gavel design rocks a wide 30mm diameter bucket that will accept beads, pills, cores and other inserts. The flat top design makes this banger accept most paddle, bubble, and ball style directional carb caps. The inner diameter of this gavel banger nail is approx 21mm wide so you will need a carb cap that exceeds that size in diameter for best results. We suggest a bubble or ball style cap as you can ensure a good seal every time. This banger is available in 90 degrees and in Female 14.4mm, Female 10.0mm, Male 18.8mm, Male 14.4mm and Male 10.0mm.