To your gas fireplace or fire pit. For gas fire pits or gas fireplaces only. You need to have a gas source. To create the flame, preferably natural gas. The glass does not actually burn! An economical way to get the look of solid-colored glass without the price! This listing is for 15 Lbs of. 35 Lbs CLEAR (aqua tint) base glass. (may vary in color and size). 50 lbs in all! Enough to fill the average fireplace. (And if it can be used, you need to respect the recommended size and amount of fireglass). Please seek professional help with installation, especially if using propane gas as it can be very dangerous if not properly installed. Ur fireplace glass crystals are made to withstand the heat of a fireplace or fire pit flame. 1/4″ means that the average size is 1/4″. Some pieces can be quite smaller and some can be quite larger, this is typical for all kinds of fireglass. Propane burners do not burn as clean as natural gas and can cause discoloration and sooting, so it is recommended to use dark colors with LP propane. The shade/hue of the glass can change dramatically in different sources of light as well as in different colors of surrounding areas, backgrounds, etc. The image of this glass may be distorted by the settings of your viewing screen. Multiple packages are not always delivered on the same day. So please be patient with them, and thank you for understanding! To calculate how many lbs glass you need: For rectangular or trapezoidal fireplace/fire pit. 1 measure the width across the center of the firebox (in inches) 2 multiply the result times the depth (inches) from the front to the back 3 divide the result by 20.5 4 multiply the result by the number of inches high you would like the glass which should be at least enough to cover the top of your burner. For round fire pit (# lbs needed): 1 Divide the diameter (in inches) by 2. 2 Square the result. 3 Multiply the result by 0.15. 4 Multiply the result by the number of inches deep. For colorful fire-glass toppings and other ideas to brighten up your fireplace or fire pit! The item “15 Lbs 1/4 BRONZE FIRE GLASS+35 Lbs Base clear glass Fireplace Fire Pit” is in sale since Friday, June 26, 2009. This item is in the category “Home & Garden\Yard, Garden & Outdoor Living\Outdoor Cooking & Eating\Fire Pits & Chimineas”. The seller is “allfireglass” and is located in San Diego, California. This item can be shipped to United States.