Renting test equipment from foreign company

Hi,

Ours is IT company registored in India, We want to rent some test equipments from company of USA, ( They are not registored here in India, they dose not have PAN). We are getting equipments from STPI route with out paying any coustems. Now qustion is what are the tax liablities on rent we pay to them every month.? Do we need to do any TDS. 

Thanks in advance for letting me know the tax rule on this.

Regards

Arun