Level Three Bit (Moderate to Strong Effect) - Level three bits are suited more for the mature horse (4 to 5 years old) with the capacity of accepting more pressure from the bit. So, thinner or twisted mouthpieces, longer shanks, non-swiveling cheeks. This category includes your curb bits. Not sever bits, but just dedicated to more experienced horses and riders. For easy recognition all Level Three bits are color coded in yellow.