The standard garage door roller has a wheel that is 1-3/4 inches in diameter. They are called 2 inch rollers because they are used in 2 inch tracks which is standard on residential and most commercial garage doors. The 10-ball bearing wheels make the rollers move smoothly through the tracks and have an average life expectancy of 15,000 cycles. The long stem rollers allow for more horizontal movement without falling out of the roller bracket and are typically used as top or bottom rollers on the garage door.