While scouting my electrical panel to see if it had any free knockouts to add a circuit to my home, I noticed that the lower-right 20A breakers are tied together with a handle. Why?

As far as I know, this breaker turns off all outlets in the master bedroom, switched plugs in the guest bedroom, and all outlets in hallway.

Is it a multi-wire branch circuit? They don't seem to share any neutrals. There are two separate white wires going to the neutral bus on the left.

I am not planning to do my own work in the panel; I'm asking for my own curiosity.

In the picture below, I traced the hot wires from the two breakers using blue and red lines.

Here is the panel diagram, which has seen...better days.

While scouting my electrical panel to see if it had any free knockouts to add a circuit to my home, I noticed that the lower-right 20A breakers are tied together with a handle. Why?

As far as I know, this breaker turns off all outlets in the master bedroom, switched plugs in the guest bedroom, and all outlets in hallway.

Is it a multi-wire branch circuit? They don't seem to share any neutrals. There are two separate white wires going to the neutral bus on the left.

I am not planning to do my own work in the panel; I'm asking for my own curiosity.

In the picture below, I traced the hot wires from the two breakers using blue and red lines.

Here is the panel diagram, which has seen...better days.

Here's the full panel:

While scouting my electrical panel to see if it had any free knockouts to add a circuit to my home, I noticed that the lower-right 20A breakers are tied together with a handle. Why?

As far as I know, this breaker turns off all outlets in the master bedroom, switched plugs in the guest bedroom, and all outlets in hallway.

Is it a multi-wire branch circuit? They don't seem to share any neutrals. There are two separate white wires going to the neutral bus on the left.

I am not planning to do my own work in the panel; I'm asking for my own curiosity.

In the picture below, I traced the hot wires from the two breakers using blue and red lines.

While scouting my electrical panel to see if it had any free knockouts to add a circuit to my home, I noticed that the lower-right 20A breakers are tied together with a handle. Why?

As far as I know, this breaker turns off all outlets in the master bedroom, switched plugs in the guest bedroom, and all outlets in hallway.

Is it a multi-wire branch circuit? They don't seem to share any neutrals. There are two separate white wires going to the neutral bus on the left.

I am not planning to do my own work in the panel; I'm asking for my own curiosity.

In the picture below, I traced the hot wires from the two breakers using blue and red lines.

Here is the panel diagram, which has seen...better days.