1. 300MM MINI RAIL:

Material: Made from high-strength, anodized aluminum (typically T6 grade 6005 or 6063). This makes it lightweight, corrosion-resistant, and durable for outdoor use.

Function: It is not a primary load-bearing rail. Instead, it is a connecting clamp that spans the gap between the frame of a solar panel and the main rail underneath it.

Profile: It has the same cross-sectional shape and grooves as the longer main rails, ensuring compatibility with all standard mounting hardware (bolts, nuts, end clamps).

2. 2PC SCREWS:

Type: These are not ordinary screws. They are typically stainless steel (e.g., SS304 or SS316 for high corrosion areas) set bolts or M8 bolts.

Function: One screw is inserted from each end of the mini rail. They thread directly into a standard T-bolt or standard nut that is already seated in the channel of the main rail below.

Purpose: When tightened, these screws pull the mini rail down, which in turn clamps the solar panel frame securely against the main rail, holding the panel firmly in place.