Hobbico 1-13/32
Sullivan 1-7/16
That little difference is huge. I mistakenly ordered the big one for my Tower (Hobbico) starter. Even after some mods, I hated the way it fit in the cone. The small one fits great.
[/quote]

I have tower starter, and i need this because on tower site under tower starter is COMMENTS: For Rubber Insert: MPRP1310(regular spinners) MPRP1320(spinner nuts)-yes, the same as Sullivan style Starters. But this is abt 9usd.
In my case i will order a cheap rubber insert and i dont know which one: sullivan or hobbico (LXFT90 or LXL401) - under 3usd.

realdo