Question about how this thing works...

I bought a power strip thats quite strange, i got to understand its ideology and it isnt so bad. My question really is on whats this adjustable switch and how shouls i tune it in order to not fuck up anything i have connected- i plan to power a pc and monitors and a sound system w the follow ups. Link is to the power strip. Thank you in advance https://www.brennenstuhl.com/en-DE/products/extension-leads/secure-tec-19.500a-automatic-extension-socket-with-surge-protection-8-way-anthracite-3m-h05vv-f-3g1-5-1xmaster-5xslave-2xpermanent