N Scale Package includes one front and one rear coupler. This conversion fits: Atlas / kato: GP-7, GP-9 Locomotives (before 1995). This kit includes a pair of 001 01 009 couplers for curved track of 12” radius or more, plus a pair of 001 01 007 knuckle & lip shanks for use on layouts with radii of less than 12-inches. Use the coupler that best fits your particular need. The coupler is assembled. If using the knuckle & lip shanks, disassemble the coupler & install the knuckle & lip shanks in the draft gear box. (Fig. 1). Note: This conversion requires the use of a #62 (.038” or .96mm) dia. tap drill, a #56 (.046” or 1.2mm) diameter clearance drill, and a 00-90 tap. These tools are available in Micro-Trains® Tap & Drill Set.