20" Round Catch Basins

We have your solution to all of your drainage needs with our new 20” Drain, Valve, & Meter Box! This box is great for large applications such as golf courses but is also a suitable size for the home. There’s no need to worry about different colored fittings or plugs to inventory because as well as accepting 2”, 3” & 4” pipe, our box can also accept 6” pipe. Our 20” Round Catch Basins will also accept Polylok 20” Risers so you can easily bring the Drain Box to grade. It is the most versatile Drain Box available on the market today!

U.S. Patent No# 6,666,349 & 6,817,631


  • Easy to install
  • Accepts risers to bring to grade
  • Accepts 6", 4", 3" & 2" pipe
  • Pipe can be installed at various heights
    Installation Instructions:
    1. Carefully cut out required opening in the box with a knife.
    2. Install seal from INSIDE the box.
    3. Screw on the nut from OUTSIDE the box.
    4. Tighten to provide a watertight seal.
    5. Remove the correct size tear out on the seal. TEAR OUT- DO NOT CUT OUT.
    6. Slide the pipe into the seal.
    7. Snap the stabilizing feet into the sockets at the base of the box. (12" only)
    Special Instructions for Installing 4" Corrugated Pipe Only:
    1. Remove the 4" TEAR OUT on the seal. TEAR OUT DO NOT CUT OUT.
    2. Carefully cut between raised ribs on back of seal in all 4 places.
    3. Push corrugated pipe into seal.

Part Number

  • 3017-20CG6 (20" D-Box, 6 Hole with Grate)
  • 3017-207G (20" D-Box, 7 Hole with Grate)
  • 3017-207C (20" D-Box, 7 Hole Custom)
  • 3017-20CG (20" D-Box, 8 Hole with Grate)
  • 3017-ME20 (20" D-Box, 8 Hole with Galvanized Metal Grate)

Similar Products

Rain Drainage Boxes

Solve drainage problems anywhere with our Rain Drain. It’s easy to use, installs in minutes and blends with your landscape. We sell the Steel forms so you can make your own Rain Drainage Boxes. We have sold more rain drain molds than any other manufacturer. Once you start making your own Drain Boxes and start making additional money, we supply the grates that go with it.

U.S. Patent No# 5,130,016

12" Round Catch Basins

The Polylok 12" round catch basin is the most versatile drainage box on the market today. You can choose what height you want your inlets and outlets to be. It also comes complete with the only seal of drainage boxes in the market that accepts 2'', 3'',4'' and corrugated pipe. No more different fittings to inventory!

U.S. Patent No# 6,666,349 & 6,817,631

Square Catch Basins

Offered in two sizes, Polylok manufactures the most versatile Catch Basin on the market. The basin comes complete with either a black or green grate, and two seals that accept 2", 3", 4", and corrugated pipe. You can choose your inlet and outlet heights, and it can accept one inlet and up to three outlets.

Goes Well With

Seals for 12" & 20" D-Boxes

Our D-Box seals are the only true watertight seals on the market today. Our 4'' seal fits in both our 12'' and 20'' plastic D-Box. It accepts 2'', 3'', 4'' and corrugated pipe. Our 6'' seal works in our 20'' plastic D-Box. No other seals can do so much!

20" x 6" Risers

We have combined all the best features of concrete and plastic risers to create our patented riser system. Our risers hold their shape, are stackable, screw together, and are water and airtight. Structural ribs inside prevent frost from adhering to the riser in frost prone areas.

U.S. Patent No# 6,655,093; 6,688,072; 6,484,451; 6,877,28

20" x 12" Risers

The best just got better. You asked for it and now we have it. Polylok is proud to introduce our 1 foot tall by 20" riser. It has the same high quality as our 6" tall by 20" risers, but with fewer screws that you and your customers have to put together.  Structural ribs inside prevent frost from adhering to the riser in frost prone areas.