This size is designed for an IBC (4' x 4') with 12" of MEDIA DEPTH (gravel, etc.) and will handle a bed up to 4' x 8'. What you get is: One 4" pvc rugged gravel shield 14" tall (slotted rather than drilled works much better due to the razor sharp cutting edges) Why waste grow bed space with a giant 6" media guard?? One 3" pvc bell x 12" high with CLEAR TOP cap and blue pull handle, (looks very cool and makes it easy to watch the action inside the bell) One pair male and female threaded adapters with "o"ring to match for the bulkhead adapter Two 1" 90s One 4" and one 6" and one 7" pieces of 1" pvc pipe (you can swap the 6" and 7" for media depth changes as well) One 1" to 2" adapter for the VERY important 2-1 "Bernoulli effect" (most siphons are NOT the proven 2-1 ratio) Set of 2 adjuster rings for instant water level changes for seeds, seedlings or critter control. Basically what you see in the first photo above plus 2 rings. These are ready to go. All you do is slip them together and install them in your growbed's 1 1/4" hole. NOTE: These are ready to install on a typical plastic 1/8 - 1/4" thick grow bed but if you built yours out of say 3/4" plywood with a liner you will need a 1" bulkhead adapter and the best price around is from Allied Aqua Dot Com. About $3 to $3.50 last I checked. That is good for up to 1 1/2" so covers pretty much anything.