I broke the peg that fits into my goodyear retractable airhose reel. Very similar to this - Goodyear 0.37 in. x 65 ft. Retractable Air-Hose Reel - Walmart.com. May also work for retractable extension cords as the pegs seem to be the same. 

Printed out of PETG with 50% infill and holding strong.