Retractable gear table slides with equalizing rack & pinion assembly automatically extend or retract both ends of table tops at the same time. One person can open tables to insert leaves while the base remains in the center. Retractable gear table slides can be used on solid pedestal or non-dividing base tables where only the top extend and the base remains stationary. Each individual wood section on retractable gear table slides measures 1" wide by 2-1/4" high. If measured at the curved arc each section is 2-1/2" high. Wood table slides are unfinished hardwood Maple.