post-free
adverb, adjective UK uk/ˌpəʊstˈfriː/ us/ˌpoʊstˈfriː/ (also post-paid)
邮资免付的;邮资已付的
used when something is sent by post without any money having to be paid
Send for an educational DVD post-free. 请来函索取教学DVD，邮资免付。
The guidebook costs £10.95 post-free. 旅行指南定价10.95英镑，邮资免付。