Displex screen protectors are sized for smartphones and tablets. The PSP (all models: 1000, 2000, 3000, Go) has a unique screen aspect ratio (16:9 for 2000/3000/Go, 4:3 for 1000) and physical dimensions that don't match any phone Displex is cut for.
Buy a PSP-specific screen protector. Search:
Brands like Hori (official licensee), PowerA, PDP, or generic "PSP [model] tempered glass" on Amazon/eBay cost $5–$15 and fit perfectly.
Protect your PSP properly—don't improvise with phone accessories.