"良品可使用" can be translated as "The good-quality items are usable" or more concisely as "Usable good products" (depending on the context, where the emphasis might be on the usability of products that meet quality standards).
If you're referring to a situation where products have been inspected and found to be of good quality and thus can be used, a more specific and natural-sounding phrase in English might be:
"These products are in good condition and can be used."
"The inspected items are of good quality and are available for use."
For a label or a brief indication, "Usable Goods" or "Good-Quality, Usable Products" would also work.