Surebonder #4 heavy duty 5/16" staples. 1250 staples per box. Fits Surebonder models: 5690 5600 5685 5800 9600A Arrow T50 Stanley TR110 TR150HL Powerfast (Swingline) 10401 31690 31890 Ace Hardware 2014413 Craftsman 68517 68492 68434 Black and Decker 8000. Use for uphostery fabric covering window coverings etc.