Kester 285 Mildly Activated Rosin Flux is classified as Type ROL0 Flux under IPC J-STD-004. This flux was formerly classified as Type RMA per QQ-S-571. 285 consists of high-quality, purified rosin, into which a synergistic combination of activating agents has been incorporated. The fluxing ability of 285 is much greater than that of ordinary mildly activated rosin fluxes and is comparable to that of fully activated rosin fluxes. 285 has been developed for use in the electronic industry where difficult assemblies are to be soldered, but process requirements stipulate the use of a mildly activated rosin flux.