Review on 25 Black Rubber Vacuum Caps for 3/8-Inch Diameter by Stephen Diaz

These black rubber caps are perfect for sealing off unused ports in my car's fuel system. As my tests showed, they provide a tight, leak-free seal that holds up well against the demands of automotive use. The caps are easy to install and remove, and they fit snugly over the port without slipping or sliding off. The only downside is that they are a bit pricey compared to other options, but the peace of mind they provide is worth it. Overall, I highly recommend these rubber vacuum caps for any automotive application.