To my mind the banana plugs are of a good quality. However I had with my speaker cables (2x2,50mm2) some problems. Without modifying the Bananstecker the speaker cables were not tight enough. Smaller movements of the cable was enough and she slipped back out of the plugs. For this cable strength the rear screw is probably a bit too short! To solve the problem I have in each case the rear screw turned out completely, a small nut (M3) put into it (between the screw and "Bolt") and the screw draufgesetzt. Now you can fix the speaker cables wonderful and they also no longer slip out.
