The T10 LED bulb is an economical one to replace T10 halogen fittings. Most used for multi-purpose 12 volts applications, including automotive brake light and turn signal light, etc. Different from the traditional halogen bulbs, T10 LED Bulb is more efficient and brighter, and its life span even longer than the halogen one. And it has different sizes for your choice.
You are purchasing single piece of LED bulb.
The term of 13LEDs or 13-SMD-LED only means the quantity of its LED chips built on the circuit board.