Plumbous Model is a common tool for detecting state of fish top in downhole and casing inner diameter. It is used in fishing operations with an assembly of a steel body and a pure lead founded at the bottom. It is designed to enable the operator to determine the configuration of the top of the fish and to locate its position in the well bore. Its use enables the operator to select the proper tools needed to successfully complete the fishing operation. Impression block is an accessory tool used to check the shape and size of the top of fish and to determine tool appropriate for fishing operation.