・ We've published a guide on how to tie the "Double Lark's Head Knot," which is "wishbone-free! Easy! Adjustable length!" First, find your preferred length with a "Lark's Head Knot," and once you've decided on the length, we recommend using it with the "Double Lark's Head Knot." ・ Since it's a 6mm hollow core, you can pass a Dyneema line through it for a bungee cord specification. #anzyproduct's Rubber List ↑ This is a list of the rubber products we sell. ＜Specifications＞ ・ Outer diameter 12mm x Inner diameter 6mm ・ Maximum elongation rate: 8 times ・ 100% natural rubber material that emphasizes stretch ・ Weather-resistant black coating to prevent rubber deterioration ・ Vacuum storage, oxygen removal, light shielding, and cold dark storage until shipment ＜For golf shafts and other slender spears up to 3m＞ → Single pull: Use at 40-60cm ＜For medium to strong shafts of 3-4m＞ → Double pull: Use a loop of 80-140cm ＜For strong shafts of 4-5m＞ → Double pull: Use a loop of 120-160cm ＜Reference＞ Start by selecting a slightly longer rubber and shorten it to find your preference. If the rubber is stiff, make the rubber slightly longer with a Lark's Head Knot. It will feel softer if you make it longer. If you want more power, adjust the rubber shorter with a Lark's Head Knot to get the maximum power from the rubber. Our rubber has ample strength even when fired at full power. The guideline is that the rubber should be about 70-90% of your arm strength when pulled from the middle of the spear's total length to slightly forward.