Needle for Injection

[Old-PM-Pumper]

Hey Guys, I just tried injection for the first time. I got a supply list from this board but didn't get info on the needle. Looking thru the pictures and post I decided to order the butterfly needle for the skull, because I thought that was what I saw in pictures. I had no results, O - nothing. I never could get any flow, even squeezing the bag and hanging it very high. I even placed it in 4 different spots (use 4 needles.) Still no flow. I wasted a bag of saline and many supplies. I'm sure the needle that I choose was the problem. Can someone give me more guidance? I would truly appreciated any help!!