Any call that makes a distress sound can work on any given day,but sometimes it wont work no matter what the sound.There are many good mouth calls,a closed reed call is the easiest to use just blow in them and make the waa waa waa sound and try to sound very pittiful and in pain.If you want an E-caller youll spend some more money.I killed my first coyote using a johnny stewart PC-1,I think,anyway it was a closed reed call that made a rabbit sound,that was 11 years ago and many coyotes ago.I now use the primo's hot dog and a foxproFX-3,there are many good calls that work,I have called in coyotes with a diaphram turkey call,trust me if you see a coyote hunting or if one is near enough to hear your calls if you sound in distress they will come,but if you move,or leave any scent in the area that he can smell before you see him,or he see's you first you probably will never know he was there.Where is your location,here in KY they always just appear out ofthe brush,or a fence row or any where and suprise you,so be ready as soon as you make a sound.GOOD LUCK!!