Kester 197 Soldering Flux is a homogeneous solution of high quality purified Grade WW rosin in a specially blended alcohol vehicle into which a very small amount of an extremely effective activating agent has been incorporated. 197 is classified as Type ROL1 flux under IPC ANSI/J STD-004 Joint Industry Standard. 197, under MIL-F-14256, was QPL approved as Type RMA.

197 has proven to be nearly as active in fluxing ability as highly activated rosin fluxes, but the flux and its residue are considerably less conductive. The low conductivity results from a minimum of ionic activating agent as shown by the very high water extract resistivity. The rosin residue is non-corrosive, non-conductive, and moisture and fungus resistant. The dry rosin residue actually insulates the surface from atmospheric corrosion.