Unless you have been rooting for awhile, the 46g is a bit harder to use. Its a true crown needle, which is triangular in shape and one barb on each of the three sides of the triangle near the tip. I can honestly say I haven't broken any of these but they do go dull after a bit so you still have to change your needle. The other needles turned out to be true crowns this time also although we ordered the one barb, these came and these work just as well as the one barb. The size needle really depends on the quality of mohair you are using. If you are using a high quality KID mohair, then the 46 or 43g will be fine. If using an older mohair, like young adult or yearling or adult, I suggest the 42g. Shipping depends on where you are located and quantity of needles.