For those who prefer a hand-mix formulation, this medium body Polyether material offers high-precision impressions. 3M ESPE 31712 Impregum F Polyether Refill. Hydrophilic before, during and after the set for unsurpassed accuracy, even in the presence of moisture. Thixotropic: it flows smoothly under pressure in critical areas and remains fixed without pressure. Snap-set properties reduce the potential for distortion during the setting process and removal from the mouth to assure a precise-fitting final restoration. Polyether material characteristics guarantee impressions of the highest precision. Monophase impression technique; just one viscosity for tray and syringe.