This is an end cap used with the Bullet Track system. Each end cap gives your Bullet Track system a professional finish. These end caps are printed with PETG which is UV resistant and are intended to last for many years to come. There are three variations available for these end caps, a blank end cap, an end cap with a threaded hole for a PG7 gland, and an end cap with a threaded PG9 gland. The PG7 and PG9 glands are also available to purchase.