Garmin DC-50?

I seen were someone posted something about the du modified dc 40 collars. If anyone is considering sending some dc40s to them I highly reccomend them. I sent them 4 collars that would start out tracking good, then eventually they would drop the collar and sometimes never pick back up on the gps. After getting them back from them they work great know. They do really hood work, very professional job. The collars look great and function awesome. I have two more collars I will be sending to them very soon. For the price you can't beat it.