Great! First time I've seen a link for buying the stuff!

Presuming that the ingredients are in order of decreasing quantity, the predominant spice is chilli powder (with quite a bit of other hot spices such as mustard seeds and black pepper):
Al Noor "Bassar Curry Powder":Ingredients: Chilli Powder, Coriander Powder, Turmeric Powder, Mustard Oil, Fenugreek Leaves, Cumin Powder, Bayleaves, Mustard Seeds, Cardamom Powder, Cinnamon Powder, Black Pepper Powder, Cloves, Fenugreek Powder, Nutmeg Powder.
Star Brand "Basaar Original" Curry Powder":Ingredients: Chilli, Tumeric, Garlic, Coriander, Cumin, Cinnamon, Ginger, Fenugreek Leaves and Powder, Bay Leaves, Salt, Brown Cardamom, Cloves, Black Pepper, Vegetable Oil.