Amazon.com: Screw Cap Covers - for Phillips and Square-X - Black (100 per Pack) : Industrial & Scientific
Aluminum Screw Caps
200PCS Rubber Caps Bolt Screw Cap Covers, Bolt Covers Caps Rubber End Caps Vacuum Caps, Bolt Screw Cover Rubber Nipple Cap Rubber Tip in 10 Sizes from 2/25 to 4/5" for Protecting