Sheffield Navigation began operations in 2020 and provides a one-year warranty on the products it sells. It estimates that 19100 of the 409000 units sold in 2020 will be returned for repairs and that these repairs will cost $10 per unit. The cost of repairing 15700 units presented for service in 2020 was $128800. Sheffield estimates that the remaining estimated units will be presented for repair in the following year. Sheffield will report