New & improved Con Forms premium quality boom pump 148mm ID (metric) gasket for concrete pumping systems. These super-tough, tear-resistant nitrile rubber gaskets are infused with an oil-free internal lubricant that promotes smooth motion while maintaining full sealing properties and virtually eliminating joint leakage. Great for use in stationary engagements, too providing easy cleaning by eliminating stuck on concrete material. Popular V-Groove internal center cavity.