I don't know what size mine are but they're about 1-1 1/4 inch and curved, they don't makw a big hole in the fabric and I have a tool I forgot what it's called but it's a small metal rod inside a wooden handle, the rod has grooves in it and you use it to open and close the pins so your finger doesn't get sore. I thought those pin jackets were for marking spots that you needed to go back to later for whatever reason.