The Standard Baluster Connectors have a hole in the center to screw them down to the cross rail (screws included).  Available for Round or Square balusters, in either Level or Stair configurations

NOTE:  Since the Level Baluster Connectors cannot be seen once the baluster is attached, they only come in black.  Stair baluster connectors come in black, white, bronze and hammered bronze

Sold in 20 packs for 10 balusters – Round Level connectors also sold in Bulk Pack of 500 Pieces