STAN came out with new features for several of its releases in 2016. Most notable, perhaps, is the training lock. The STAN releases that end with "TL" let you know they inlcude the training lock device.Basically, this is a pin that doesn't allow the hook on the release to open. So you can practice shooting with your own bow, include the release, but the string will stay captured in the hook.Also, STAN is making many of its releases available in the new heavy metal finish. It's a copper-based finish that makes the release good and heavy for maximum feel in the archer's hand.