End Collar - The End Collar will save your light fixture or accessory by preventing the pin from slipping through the grip head if it ever loosens unexpectedly * Knurled Recess - The Knurled Recess machined in the pin gives you better grip and prevents light fixtures and accessories from slipping * 1/4"-20 & 3/8"-16 Female Threads - The head of the pin is tapped with a 1/4"-20 thread and the collar or "tail" end of the pin is tapped with a 3/8"-16 thread