O-ring specs

[axxel57]

If you can do that trick with a BUNA 90 o-ring on a bulletnose spool, I bet they`ll invite you for a TV show......

 

[NotSure]

I think you're likely to draw blood if you use your palm and a duro 90 o-ring. I lay the lubed o-ring on my computer mouse pad and push the spool down on it with the spool at a 45 degree angle.

 

[redacted]

I use my thumb with duro 70/75. Too much pain with duro 90s, even in the hand holding the spool.

 

[axxel57]

I use the Trident or Scubatools base for spools. Buna 90 on shouldered or classic spools no problems by using both thumbs.
Two out of three Buna 90s break before I get one installed on bulletnose spools, so I use only Buna 70s for them.......