Fits on any sized deck or fence railing from 1" To 4" Wide; Please measure your railing to make sure it's 1" to 4" wide. Works on chain link, wrought iron, composite, and standard wooden rails Planter arms are adjustable and lower stabilizing foot keeps planter perfectly level, regardless of fit Water reservoir holds 6 cups of water with auto-overflow; hidden tray separates plants from reservoir; with slits to allow only the roots to reach the water reservoir below; avoiding root rot. Excess water drains out the lower leveling support foot channel, no drilling is required. Hidden tray separates plants from reservoir; with slits to allow only the roots to reach the water reservoir below; avoiding root rot IMPORTANT: Arms must be fully seated for Pins to slide into position. IMPORTANT: Please measure your railing to make sure it's 1" to 4" wide. IMPORTANT: Excess water drains out the lower leveling support foot channel, no drilling is required. For Installation Assistance Call 1-888-215-4024