Not sure I understand the question and the first reply here....If you ordered a steel breech kit from Crosman it will come with a suitable bolt probe and knob.. providing you ordered the one for the .22.Some folks choose to buy an extended probe to push the pellet deeper into the barrel and past the transfer port hole. That's a personal preference.More importantly is the position of the tiny screw hole that secures the steel breach to the tube. Some are forward in the pellet groove and some sit back under the probe. (can't remember for sure without checking but I think it requires the forward screw) someone will verify.