MHJ Seismic Exploration Bits

          MHJ Scratcher                                          MHJ Step

 Size or OD: 3 1/2" to 4 1/2"                   Size or OD: 3 1/2" to 4 1/2"

Box Type: 2 3/8" Mayhew Jr.                 Box Type: 2 3/8" Mayhew Jr.