O rings to lock drill in High

[Nuts4FIRST]

I'm not exactly sure which size O ring is needed to lock the gearbox in high gear. At the time I made the discovery I had a handful of rings and used what ever fit.

Here is what I think I used, Small Parts number: U-ORB-218 (1-1/4" ID x 1-1/2" OD x 1/8") use two of these stacked on top of one another.

I've recently found that metric sizes fit better (purchased at a local store) but Small Parts doesn't stock those, so they are against the rules.

Chris Mikus