Remember though, it is likely there exist tricycles with a pedal design with which the universal blocks will not work.

After securing the pedal blocks with flex bands, the pedals keep swiveling to the ground and you can't keep them from doing that,

Installation was a little challenging as these are designed to have a tight fit on the pedals, it took me about 5 minutes to install both extensions and part of that was trying to figure out how to keep the pedals still while working the blocks in place

I bought these for a Fisher Price Tough Trike and the pedals on that are not like standard pedals on a regular bike or trike so they don't exactly fit firmly