DH ITEM# 590-2000 - Quick, easy two-bolt or weldable installation on any flat surface. Rust-proof heavy duty polymer case protects battery and charger from elements and corrosion. Galvanized metal mounting bracket and locking bar provide secure battery protection. DH ITEM# 590-2018 - Quick, easy one-bolt installation on jackpost or A-frame - no need for cutting or drilling. U-shaped clamp style fastener mounts over most trailer tongues. Rust-proof heavy duty polymer case protects battery and charger from elements and corrosion