SIWI Top-Cover BENEFITS OF SIWI TOP-COVER More space: SIWI Top-Cover provides you with the option of filling more grass or corn in the trailer. Maximum yield: SIWI Top-Cover minimises crop waste, so you get the most out of your field and your machines. Fast ROI: When you invest in SIWI Top-Cover, you will recover your investment in the first season.. Inexpensive operation: Minimal maintenance costs. Extremely flexible: Can be used with many types of trailer via the intelligent modular design. Legal transport requirements: The roof can be folded down, so the height of the grass trailer can be reduced for legal requirements. Previous Next Ready to get started? BUILD YOUR SIWI