The Dillon Precision Press Frame Kit Assembly allows you to upgrade your RL450 frame or perform an entire upgrade of your RL450 to an RL 550C. This same kit is an upgrade to the RL 550C that contains threaded upper pivot pins. IncludesRL550C FrameToolhead2 Toolhead PinsPrimer slide return spring and pinPlatform Alignment ToolPunch for removing old-style link arm pivot pinsTwo New-Style Upper Linkarm Pivot Pins