The kywoo3D has always been concerned about product quality.We are developing products and working hard to improve the quality. Some of our products may be more expensive than others,but please believe in our quality and believe that you will not regret when you receive the goods.●All 3D printers have 12 months warranty, Please buy it with confidence!●Overseas after-sale engineer service is available, please contact our online service if you have any questions.●You can get full video help by search "kywoo3D" on YouTube.Package Included: 5 * Limit Switch.