Machined aluminum plug (end cap) that pressure fits into schedule 40 pipe. The outside diameter of the plug covers the end of a fitting. See below for different sizes that these end caps are avilable for and see picture of fitting inside pipe which is then lined up with the fitting.
Note that the 2" IPS Plug has a different design than the others. See picture below.
• Quick and easy way to assemble structural pipe systems • Reduce labor costs by 70% • 100% reusable • No welding or threading • No drilling or bolting