The Good Manner KF94 is a line of KF94 masks produced by Handa Healthcare (한다헬스케어), a South Korean company. Good Manner masks are made in variety of sizes, colors, and shapes. Good Manner masks are approved KF94 masks.
The Good Manner KF94 come in two different styles: the "2D" bi-fold style, and the "3D" boat-style. Good Manner masks come in adult / large, medium and kid sizes. For the boat-style, colors available are: white, black, brown/beige, gray, pink and yellow (for kids). For the "2D" bi-fold style, beige/brown, pink, gray, black, and white colors are available.
The Good Manner masks don't have built-in adjustable ear loops - it's expected that most people will add mask cord locks or a behind-the-head ear-saver to achieve a tighter/better seal.
The Good Manner KF94 masks are all approved KF94 masks, so quality is enforced by the South Korean FDA. But several independent groups have tested Good Manner masks:
Aaron Collins, an engineer with a background in aerosol science, tested the Good Manner KF94 mask and found 99.85% filtration and a pressure drop of 0.3 inches of H20 as-worn. Collins also wore the Good Manner mask while performing different steps of a quantitative fit test (2:37 timestamp) and achieved > 99% filtration as-worn in all steps except talking (98.74%).
Lloyd Armbrust tested the Good Manner mask and found a filtration efficacy of 99.64% and a pressure drop of 108.8 pa.
James Scott, a professor of Occupational and Environmental Health at the University of Toronto tested the Good Manner KF94 in a report with CBC news. They found a filtration efficacy of 99.2%, 99.6% and 99.9%, and used a TSI 8130A filter testing machine with a flow rate of 85 liters/min and a salt aerosol.