off-the-shelf

In finance or when buying things, off the shelf refers to products that have already been designed and made, compared to "made to measure," (or "one-off," "custom-built," "custom made," etc.), which refers to products that have to be made to a special order.Off-the-shelf products are generally cheaper and more quickly available than made to measure.In the manufacturing of clothing, equivalent terms are off the rack, ready-to-wear, and prêt-à-porter.
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Adjective
1. (especially of clothing) made in standard sizes and available from merchandise in stock; "a ready-made jacket"; "ready-to-wear clothes"
(synonym) off-the-rack, off-the-peg, ready-to-wear
(similar) ready-made

slang. หาได้ง่าย, มีไว้พร้อม