double tapping on 2 pole breakers

[kwired]

We can't see the breaker ratings in the photo, but are you saying that the visible portion of the lug in the photo isn't enough to differentiate between the two styles?

Judging by the apparent size of the #10 conductor on the surge protector, the breakers in question have #8s or larger going to them, which would suggest they are 40A or above.

Cheers, Wayne

having #8 conductors does suggest it may possibly be 40 amp or above breaker, but visible portion is also sufficient for anyone that is around QO breakers a lot. That obviously (to me) is not 30 amp or less because the terminal looks different than what is shown on those. It has a square washer or pressure plate under the screw head and one conductor can go on each side of the screw. The 30 amp and less also listed to accept up to 8 AWG conductors BTW.

35 amp and higher are a box lug with binding screw that tightens down directly onto the conductor, similar to what many other brands do with nearly all sizes/types.