HEAVY-DUTY LEVELING JACK FOR 4X4 POSTS - Designed to support up to 15,000 lbs, this steel screw jack stabilizes beams, levels joists, and reinforces crawl spaces. Built for demanding structural repairs, it offers strength, stability, and durability for residential and commercial applications. ADJUSTABLE & VERSATILE SUPPORT - Easily attaches to 4x4 nominal lumber with a 6-inch adjustment range for precise leveling. Functions like a lally column for structural reinforcement, making it ideal for trench shoring, construction, and foundation repair projects. SECURE & DURABLE CONSTRUCTION - Made from high-carbon steel with a corrosion-resistant finish, this 4x4 jack ensures long-term stability in extreme conditions. A built-in safety lock provides extra security, making it suitable for both permanent and temporary support. PRODUCT SPECS & MATERIALS - Weighs 12 lbs with a max load capacity of 15,000 lbs. Features a 6-inch adjustment range using a 1.25-inch Acme threaded screw, independent swivel base plates with 4-5/16" diameter holes, and a lock-set screw for stable, long-term support. TRUSTED QUALITY SINCE 1951 - Ellis Manufacturing Company has provided industry-leading structural support solutions for over 70 years. Renowned for durable construction materials and superior craftsmanship, Ellis is a trusted name in shoring and foundation repair.