Review on Seamless Testing with the SIOUX CHIEF 6ER16 Test Plug by Fernando Beck

I use this 3 inch test plug on my boat's main drain in the bay. The boat only sails in salt water, so the all-plastic construction is a big plus. the plug was plastic/metal and after a few uses the metal "froze" due to corrosion and was no longer used. I've since bought a second one as a backup. Excellent value for money and quality.