No-Hub Couplings. Engineered to connect no-hub cast iron pipe. The No-Hub Coupling has a patented shield design that provides maximum transfer of pressure from the clamps to the gasket and pipe. Engineered to connect no-hub cast iron pipe in applications, replacing the less-efficient hub and spigot. Gotcha, yes, I am aware that Mission and other companies make the flex couplings, but it seems like Fernco is the Kleenex of those--I apologize in using it generically. I most likely will go with the SJ glued fitting, but I might need some flex at some point in connecting the pipes (not necessarily on this particular use), and was told they are ... A.Mike Casey, a licensed plumbing contractor and co-author of Code Check Plumbing, responds: Often referred to as Fernco fittings (after the name of a major manufacturer), flexible neoprene and elastomeric PVC couplings are available in dozens of sizes and configurations. They’re designed for nonpressure (drain, waste, and vent) applications ... If I use the Fernco coupling can this be put into the ground and cemented over. And is there anything special that needs to be done to it before I do so. Or do I user a PVC repair coupling. Fernco products are manufactured articles, which do not result in exposure. to hazardous chemicals under normal use. Fernco, therefore, is exempt. from the requirements for preparing Material Safety Data Sheets and sending. M.S.D.S.'s and labels to downstream purchasers of our products. -Fernco is a brand that makes all manner of couplings. Buying a fernco rubber unshielded coupling is not advised for this. However, the products I linked are Fernco-made products, but are shielded couplings rated for the purpose.