Based on this product's specifications, here are some alternatives and similar models
End cap Siemens 5ST3766 for electrical terminal blocks, model 5ST3766
Summary description:
Siemens end cap 5ST3766 is a replacement accessory designed for use with compatible electrical terminal blocks. It provides a protective closure for exposed terminal ends, helping to prevent accidental contact and maintain tidy wiring. Suitable for industrial and electrical installation tasks, it aids safety and organization in control cabinets and junctions.