Tom from SWISCO responded:
September 20, 2019
That's not our 15-111 pivot shoe. That looks more like our 15-199, which itself is compatible with both the Series 160 and Series 165 spring. You should measure the thickness of your spring to confirm the better match; the Series 160 is 1/2" thick and the Series 165 is 3/8" thick. As for the stamp, there will be a number printed on the old spring that you can use as a reference. |