Product Description The spiritual cousin to Jimpy's discontinued Space Invaders, these Benchmade 51 spacers are made in-house from a rubbery, shatter-proof polyurethane. They extend and protect the handles of the BM 51, and enable adjustable balance with up to 2x removable tungsten weights per spacer. The adjustable weights allow you to adapt your BM 51 to suit your specific balance preference, no matter what scales or blade you are using. Assembly Instructions Remove the stock spacers and pins. Insert the Zippy spacers, and then use the stock spacers as a guide by wedging them into the channel below the Zippy spacer. Tighten the handles until they press upon the stock spacer, and then remove the stock spacer from the channel. Features Extends handle length from 5.1" to 5.6". Protects your handles from hard drops: Spacers are made from a shatter-proof polyurethane. Adjustable balance: Each spacer houses up to 2x removable Tungsten weights which enable you to find the perfect balance to suit your preference. Positive jimping for extra grip on ladders and chokers. Each spacer weighs 0.090 oz empty, or up to 0.132 oz with 2x tungsten weights installed. For comparison, a stock Benchmade 51 spacer weighs 0.111 oz. With stock scales, Zippy spacers let the BM51 weigh 3.173 oz (empty) up to 3.258 oz (with all 4x weights). Recommended Balance Configurations If you wish to use these spacers with the pocket clip, I recommend you counterweight the safe handle spacer with both Tungsten weights to compensate balance for the additional weight of the clip.