（商品）试用，不满意可退货
If you buy something on approval, you can return it without payment if it is not satisfactory.
The new manager introduced the practice of shipping items on approval.
They went into town and got two digital radios on approval.
Librarians often want to see books before they order them, so the system of obtaining copies on approval is common.
There are specific tax rules for goods supplied on approval.
There is an element of trust involved when retailers send out goods on approval.
See also: approval (GOOD OPINION)