The SO-270 Proving Ring Penetrometer is used to determine the penetration resistance of soil layers. It includes a steel penetration rod and cone for penetrating the soil, along with an aluminum handle and wooden carrying case. Additional items like a moisture content test set, thin box, and hydraulic oil are required but not included in the set. The dimension of the penetrometer is 65 x 35 x 20 cm and it has a gross weight of 10 kg.