[kaos]

your wrong about sim for sprint. the sim unlocker for sprint is so you can use any u.s gsm carrier sim with it. it will not work with out it being unlocked. sprints only works with non u.s carriers for sim. for when you travel out side of u.s . why the unlocker is made. as for calling carrier to unlock sprint wont do it. verizn does sprint wont. you will need sim unlocker.