?YUELONG TEAM SERVICE - We are dedicate to provide the 100% satisfaction guarantee. If for any reason you are not fully satisfied about the assorted cartridge needles. Please contact us, we will help you to solve your problems. Return it for a full refund or exchange are acceptable. ?GREAT QUALITY - Made of 316L surgical stainless steel and medical-grade plastic.needle bar design is more advanced,letting the needle contact skin without dead spaces. Fast rebound, One piece needle allows for maximum stability and control. ?NEEDLE STEADY - High quality silicone gel replaces iron spring, keep the needle elastic.Safety membrane can stops ink from passing through to the tube or machine.Cartridges body with Semi transparent,make it easier to observe the needle striking. ?SAFETY COMPATIBLE - The cartridge needles are compatible with various kinds of rotary machine pen. Safety membrane inside cartridges system, that stops ink from passing through to the tube or machine. ?PACKAGE and SIZE - Each box of 100Pcs. All cartridge needles are pre-sterilized, individual packed in blister pack ,disposable use only. Mixed cartridges needles : 1203/1205/1207/1209/1211RL; (each size 20pcs).