It costs about 2000 rs.
Its a device which has a USB host, so you can use flash disks, memory card readers, or an external powered USB-CDROM.
It reads FAT filesystems to get all MP3 files and transmits them over FM radio waves.
You can use any FM radio Car, Mobile, old stereo, walkman etc. which can tune into the broadcasting frequency although range is maybe 10 to 20 meters at max.
I bought one before my Cuore arrived to listen to MP3s but when I got mine it already had a CD-MP3 player.
The billionton one available here has very basic controls and even lacks a RANDOM play mode but more convinient than burning a CD. On the other hand you already get MP3 CDs for every taste including religious speeches, so you do not need to transfer those files to flash drives if you go that route.
I like the gadget because it is small and does not attract attention of crooks, even if you forget it in the car.