As to the warranty for the disposable shoe cover dispenser,normally it is one year since we  deliver out the goods. If you meet problem with the machine, you can send us video or picture to explain the problem, we  will teach you how to solve it. If it need to replace spare part, we will provide spare part for free if  within warranty, but the delivery of the spare parts should be arranged by customer. As to the formal order. such as 20pcs, we will provide some free spare parts in advance, when meet  problem ,technical people can replace spare parts by themselves.