Another advantage of the SML-D15 is the wider operating temperature range. Standard LED’s, like the SML-D1, have operating temperatures of -40°C to 85°C, while ROHM’s Single Rank SML-D15 series LED’s have an operating temperature range of -40°C to 100°C. The higher temperature range makes the SML-D15 Series of LEDs perfect for use in industrial equipment.