These are red chillies usually dried and either used whole as a spice or ground down as a chilli powder. Kashmiri chillies are known for their deep vibrant red colour and their mild smokey flavour.
This is definitely my choice of chilli powder, beautifully red with a gentle warming heat. This chilli variety is great for making spice pastes too. By rehydrating them in hot water to soften them they create wonderful red chilli paste. When using them whole they should be treated as a whole spice and tempered in oil.