Nails are available in a variety of sizes and both male and female joints. Universal nails are also available, Universal nails can be used with both male and female connections that are 10 mm, 14 mm and 18 mm. They also come in a variety of materials, such as quartz, titanium, Stainless, and ceramic!18mm Female Titanium Banger Style10mm Female Ceramic Domeless NailUniversal Titanium Nail with Attached Carb CapUniversal Titanium DomelessQuartz Nail for 18mm Male18/14mm Universal Domeless NailTitanium Nail for 18mm MaleUniversal Anodized Aluminum with Quartz Dish for E-Nails18/14mm Female Ceramic Domeless NailTitanium Nail for 14mm MaleQuartz Nail for 10mm Male18/14mm Universal Domeless NailQuartz Nail for 14mm MaleTitanium Nail for 10mm Male