The Lisle Corporation Time Saver Flat Brushes, Nos. 89610, 89620, and 89630, each incorporate a strain-fighting ergonomic design. For a firm grip, the brushes have a durable, injection molded handle with a ribbed design. All three models also have long-lasting, stiff Trialoy polyester filament that can be used in either solvent- or water-based cleaning solutions.