The Tough One!- Injection molded . Exceptionally strong and non-corrosive in a septic environment.- Easy to install - patented snap-in seal simplifies installation.- In a septic environment, no other material can match High Density Polyethylene in delivering a lifetime of trouble-free service. Tuf-Tite Distribution Boxes are injection molded, using only premium HDPE which contains no filler or foam.- The heavy-duty HDPE lid is ribbed and domed for exceptional strength. Slotted sides interlock on the Distribution Box to assure a tight fit.- Plugs and Adaptors sold separately!