The torque of the hand is large, making it easier to the hot bed. And our knobs are made of plastic material, make the leveling is safer and does not hurt the hand. The leveling kit includes 4 x upgrade leveling nuts, 4 x mold springs, and 4 x screws. It will saves you time to buying accessories separately, and don’t have to worry about the accessories match or not. leveling knob kit can make the printer much more stable and makes hot bed becomes much steadiness when printing. It only takes a few steps to up, very easy to install. Safe to use and easy to operate. Features - Color: Assorted Color. - Material: Plastic and Metal. - Size: 2 x 0.8 x 0.8cm/ 0.79 x 0.32 x 0.32 inch. - Built-in nut, high strength, more durable, integrated molding, independent research and development mold design, stable structure, high precision. - Fine process : 3D hand leveling nut is fine surface, smooth thread, deep thread, even force without slipping, flat without burrs, makes platform more stable and easier to level. - materials: Upgraded hand were adopted environmentally friendly plastic, using environmentally friendly plastic, hot-bed nut with hot-bed spring, screws which no rust, high hardness, corrosion resistance, pollution-free. - leveling kit make the printer much more stable and makes hot bed becomes much steadiness when printing. - It compatible with most 3D Printer Bed,the die springs are stiffer than ordinary spring, which help your 3D printer much more stable while printing. It only takes a few steps to up, very easy to install. Safe to use and easy to operate. Package list: 12 x nuts 12 x springs 12 x screws