SFS Standard Enlarge Quantum Field [one-action] Feat 6

Source Player Core pg. 171
Your quantum field slowly encroaches on reality. Increase your quantum field’s radius by 10 feet. Until your quantum field deactivates, once per turn when you Sustain the quantum f ield, increase its radius by an additional 5 feet (to a maximum of 50 additional feet)

Traits

Anchoring:You can use abilities with the anchoring trait only while your quantum field is activated. If you use the ability on your turn, in addition to their stated effects, they automatically Sustain your quantum field.
Concentrate:An action with this trait requires a degree of mental concentration and discipline.