Using your SmartMax Power Vehicles is easy! First, start by picking out the bars you want. Remember, cold - colored bars and warm - colored bars attract each other, so use this to connect the pieces. The vehicles click into place easily, so just line them up and press gently. You can mix these vehicles with other SmartMax building sets you might have. When building your truck fleet, get creative and try different combinations. As for safety, keep small parts away from children under 3 to avoid choking hazards. To maintain your set, store the pieces in a dry place after use. If they get dirty, you can wipe them clean with a soft, damp cloth. Have fun building!