These are Net Hangers from Cimarron Sports - hardware used to attach your batting cage net to your frame.

Features:

• Come in a pack of 25
• Each net hanger includes 1 carabiner with an adjustable rope
• Carabiners measure 2 3/4" long
• We recommend using 1 net hanger every few feet
• Attach carabiners to the roped border of your batting cage net