Gravity lock pins are simple devices that allow you to adjust telescoping tubing. Telescoping tubing is used in scaffolding to adjust the height. Masonry Direct offers the best building supplies online. Our masonry company has over 100 years supplying masons and construction workers with the best supplies available. From concrete hand tools and steel angles to stucco products, ladders and scaffolding, sealants, aggregate, and more, we've got your needs covered. Whether you are looking for hand tools or insulation, we've got your needs covered. Check out all of our construction, building, and masonry supplies online today!