You cannot buy a physical "Renault Pre-Code Calculator" device. It is a feature within larger software suites. Here are the market leaders:
Dealer/Manufacturer diagnostic tool (most reliable) RENAULT PRE-CODE CALCULATOR
The tool runs the algorithm assigned by the manufacturer. Output: You receive your 4-digit unlock code (e.g., 1842). Step-by-Step Guide: How to Get Your Code You cannot buy a physical "Renault Pre-Code Calculator"
Turn on the radio and press buttons 1 and 6 simultaneously for about 5 seconds. The Pre-code should appear on the display . RENAULT PRE-CODE CALCULATOR