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. The ELLIS Adjustable 4x4 Screw Jack is a versatile and heavy-duty product, designed to provide structural support in various applications such as residential, commercial, trench, and collapse rescue shoring. Constructed with high-quality steel, this screw jack is built to last, with a safe load capacity of 15,000 lbs. It is easily adjustable, allowing you to create an adjustable support of any length with your own 4x4 lumber. The 'U'-shaped handle enables you to adjust the height effortlessly, and the safety screw can be locked in for long-term support. The screw jack is equipped with a safety lock that can be tightened with an Allen wrench once the final adjustment has been made. With a weight of 12 lbs, minimum overall height of 14.25", and 1.25" dia. Acme threaded screw, this product is a reliable choice for your construction needs. Trust in ELLIS, a leading manufacturer of construction materials since 1951, dedicated to providing unbeatable quality, affordability, and customer service.