The trailer mechanical disc brake calipers have two configurations, forwarder pull and centre pull. The forward pull is commonly used on beam/spring axle, and he centre pull is used on independent/torsion axle. This mechanical forward pull disc brake is old version, it is usually called as boat trailer mechanical brake caliper. It has a hot dip galvanized cast iron caliper body with two pieces non-asbestos semi-metal brake pads and a straight lever. Cast iron and stainless steel are available. All trailer brake calipers provide corrosion resistance and rust protection, which are advantageous to prolong the service of marine trailers.