Assembly Instructions Product Description Adjust the weight distribution of your Seeth Designs Reblade for the Nabalis Vulp with this custom-made Zippy balance mod. This mod consists of shatter-proof polyurethane inserts which add spine weight to the blade for increased momentum and increased chaplin stability. Features Adds blade and spine-weight to the blade for increased momentum and increased chaplin stability. Includes both weighted and unweighted spine inserts so you can adjust the balance to suit your preference. Blade inserts fit the Seeth Designs Reblade for the Nabalis Vulp perfectly and won't fall out on hard drops. Bottle opener plug will fall out on drops. This insert is to protect your finger during accidental bite-handle chaplins. I recommend securing this piece with clear packing tape. Shatter-proof. Comes with a bite marker. Inserts weigh 0.055 oz (unweighted), or 0.078 oz with weighted spine insert. Bottle Opener plug adds an additional 0.07 oz.