The RPM3 is the second generation of digital pressure monitors originally offered by DH Instruments. It's a configured product, one or two transducers per enclosure, with pressure ranges from low absolute pressure to 40,000 psi (280 MPa). Except for a few select applications this product is obsolete and replaced by the RPM4.
http://us.flukecal.com/literature/product-manuals/rpm3-operation-and-maintenance