Pequin (or piquin) is a small oval shaped fruit around 1.2 - 2cm in length which has a medium to medium-hot bite (60,000 to 100,000 Scoville Heat Units). The flavour is a little citrusy and slightly smoky and is perfect for drying and crumbling over pizza or other dishes as it's flesh is quite thin and is easily dried. Throw fresh pequin chiles into soups or stews as they will impart a lovely heat throughout the dish and burst of heat if diners choose to eat the pods.
The famous Cholula sauce is made from pequin and de arbol chiles. You could try making your own as the plant is quite prolific.
The pequin plant has a compact habit growing typically 0.3–0.6 meters tall, with bright green, ovate leaves. Like most chiles, fruits start out green, ripening to brilliant red at maturity.