David B. Benson asked for a characterization of the category P of presheaves on a space X, which is sandwiched between the categories S of sheaves and E of presheaves. P is just the epi-reflective hull of S in E. (All epis in E are regular.) J"urgen Koslowski Department of Mathematics Kansas State University Manhattan, KS 66502 koslowj@math.ksu.edu