BURNER: Choose a burner that will give you approx. 6” all the way around from the edge of the burner to the edge of the fire pit. Example, a 24" burner fits in a 36" fire pit with 6" all the way around from the edge of the burner to the edge of the fire pit. (36" inside dimension of the fire pit minus 12" which is 6" on each side of the burner equals 24" so the 24 inch burner fits best. Bigger is not alway better. a 30" burner will fit with 3" to the edge of the fire pit, but pets or children walking by might be too close. Bring the gas pipe into the fire pit and into the key valve then take the gas pipe to the center of the fire pit and install the 12” flex hose on the gas pipe going directly up the center and put some tape over the end of it so that no lava rock or pea gravel gets inside it while filling the fire pit. Then you can install the burner on the flex hose and this will allow the contractor to get it centered properly and laying on the lava rock. You can get the key valve in either chrome or brass and I would get the angled valve so that the output gas pipe goes out towards the middle of the fire pit. https://fireonglass.com/collections/burnershttps://fireonglass.com/collections/burners/products/12-whisper-quiet-stainless-steel-flex-hosehttps://fireonglass.com/products/fireplace-key-angle-or-straight-valve-polished-chrome-or-brass-3-4GLASS: Use our Fireglass Calculator to calculate how much glass you need. Normally you want between 2" and 3" of glass. https://fireonglass.com/pages/fireglass-calculatorChoose your color of glass from here: https://fireonglass.com/collections/fireglassLAVA ROCK: Use our Fireglass Calculator to find out how much glass you need for 1" of fill. Lava Rock is exactly half the weight to fill the same space, so this will give you 2" of lava rock which is perfect. This makes a nice bed for the glass to lay on and keeps the heat from the pea gravel since any type of rock will pop or explode if it gets too hot. Do not use Sand as a filler despite what other companies tell you, they have no experience if they tell you to use sand, Sand does not drain water like pea gravel, and sand over time will compact and the glass and everything will slowly end up below the burner after a year or so. https://fireonglass.com/products/3-8-small-black-lava-rockTo construct a fire pit, fill the fire pit with Pea Gravel up to 6” from the top of the fire pit. Pour the 3/8” lava rock on top of the Pea Gravel to keep the heat from the Pea Gravel. The burner will lay on top and be supported by the Lava Rock. This puts the burner approx. 4” from the top of the fire pit. Pour the glass over the burner and this will put the top of the glass approx. 1-2” from the top of the fire pit. Looks nicer to see the glass from around the area and not have to look down in a hole so we like the glass near the top. The only concern is if it is a really windy area, then lower everything about 2-3” to give the flame some protection from the wind. Call us if you need assistance, we are always glad to help you and make sure you get the best installation and only do it once. 888-810-3473