The insert system refers to the type of receptacle found on the sole of your golf shoes. The insert system also determines the type of cleat that will fit your golf shoes. This model utilizes the Fast Twist 3.0 cleat system with Pulsar spikes. The Fast Twist 3.0 cleat system is the most advanced insert system on the market. The lower profile design offers improved comfort while still securing each cleat with consistent torque for maximum comfort.