For CR-10 CR-10S , ender series and many others 
see full draeing in the images
fits: Bowden Extruder 1.75/0.4MM Nozzle
bore diameter 4.1 ( it means the PTFE tube passes trough up to the nozzle)
 
this kit includes : 
1 ptfe connector
1 heatsink
1 heatbreak
1 heat block
1 nozzle