Product Description Improve the balance and deepen the sound of your Maxace Phantom v1 balisong trainer with this Zippy blade insert. The insert houses up to 4x removable tungsten weights which enable the Phantom v1 trainer to have a more neutral (less handle biased) balance profile. Assembly Instructions With the textured or holographic side of the insert facing up, use your thumb to press the inserts down into the blade, ensuring the edge lip is flush with both sides of the trainer blade. Tip: it is easier if you wedge the top/bottom ends of the inserts into place first, and then press the middle flush with the blade. Once the inserts are installed, place the ball weights on a flat surface and pop in each weight by pressing the blade down onto each weight. Features Added tip weight provides for a more neutral balance. 4x removable tungsten weights enable you to adjust the balance to fit your preference. Secure fit: won't fall off on hard drops. Deepens sound: eliminates high pitches. Shatter-proof. Compatiblewith Maxace Phantom v1. Comes with a bite marker. The Zippy Insert Mod adds 0.149 oz with all 4x weights, bringing the Phantom's weight from 3.803 oz (stock) to 3.952 oz (with inserts). Recommended Balance Configurations My preference for the balance is to use all 4x ball weights and both inserts. This provides the most neutral balance configuration. Slim caps are not compatible with the Maxace Phantom trainer (the Phantom handles are too slender). Disclaimer Phantoms have a considerable variation in closed handle gaps. Consequently, I have revised the insert design to accommodate all handle gap variations. Please refer to image 3 to view the insert geometry you will receive.