Abstract: An apparatus is for use in connection with an implement for being inserted into a vascular space. The apparatus includes a body having a passage adapted for receiving the implement. A counter is provided for counting the amount the implement moves through the passage of the body. A kit may include a first counter adapted for use with a first device having a first diameter for being inserted into the vasculature, and a second counter adapted for use with a second device having a second diameter for being inserted into the vasculature. Related methods are also described.