Magnavox D8443 switch help

Just got my Maggie D8443 in the post and am about to open her up and saw this. This may be a stupid question, but does anyone know what this switch is. I know that this has 3 amps, but I didn't know if this has anything to do with it.






thanks for what I am sure will be quick replies explaining this switch to me

It's some kind of "beat cut" for recording.....

Beat cut for recording am stations

2 replies under 10 mins...I love this board. Thanks guys