The rugged APT Clay and Trench Diggers are used for digging clay, shale, hard pan, and frozen ground. The Model 118 is most commonly used for clearing out dirt under existing foundations and for tunneling under existing structures. The Model 118 can be used for horizontal and for vertical work. The Model 119 is the perfect tool for digging trenches to lay pipes, phone lines, for foundation work, etc. The only difference among the APT Model 117 Paving Breaker and Models 118 and 119 is the handle, they have the same cylinders and the majority of internal parts in common, this makes them very versatile tools for use in various types of work. The Model 125 is a lighter weight tool ideal for digging medium to lightly packed soil, for light demolition work and for tunneling around existing foundations.