I think FastLane or PartsShop has the Bosch inserts (what you bought) as well as the complete blade. Simply detach from the wiper arm and replace the whole unit. Save the inserts you have and next time you need to change you should have the tensioner strips.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.