Now and again I need a shortish tiller extension and last year bodged one I'd had for ages onto the rather fat twistgrip of our Suzuki DF20AS. Right pain though as the fixings were too short so had to use a jubilee clip which added to the faff of fitting/removing.... and it looked a mess.
As part of this year's pre-season jobs I searched for a tiller extension that would fit... not only for diameter but the DF20AS has a damping weight at the front of the twistgrip that means to get a decent fit a longer "socket" is needed on the extension.
Most places said it was the popular standard type or nothing.
Then I tripped across a review on the YouTube channel of a Russian Suzuki dealer who has loads of great stuff uploaded. He compares the standard extension most sell with one for an"extra large handle" and shows fitting it to a DF20A.
Struggled to find someone who both stocked them and understood there were two different types but eventually ordered from Marine Tech in Norwich after ensuring they were not going to just send me the first tiller extension they picked up.
*My old bodged extension below.