This bracket is most similar to these products (adding multiple links in case one or more go dead in the future):

• LEVOLOR Trim+Go 2-Piece Universal Brackets
• Plastic Hold Down Bracket for 2" Wood and Faux Wood Blinds
• Cutelec 16pcs Hold Down Bracket Bottom Rail Hold Clips White Plastic on 1inch Mini Blinds
   

The printed pieces are quite strong in PLA if you follow my printing tips: 

• Choose extrusion width and number of perimeters such that model is 100% infill of only perimeters. 
• Use a brim and/or supports on build plate only. Parts with such a small footprint on the build plate often need a brim to remain stuck while printing. 
• ALIGN SPECIFIC EDGE TO BUILD PLATE. See my GCODE and GCODE screenshot for details. This orientation during printing ensures that the stresses the small male knob of this bracket will experience are directed perpendicular to the printed layer lines.