The built-in step allows additional pressure to be used to drive the probe. Both offer a 254 mm (10") comfortably gripped cross handle, but the cross handles on the two-piece models are detachable with a 15.8 mm (5/8") threaded connection and a 25.4 mm (1") O.D. Made of 4130 chrome molybdenum steel with hardened tips that cut a soil core 12.7 mm (1/2") diameter by about 304.8 mm (12") long.