1 bag of MakerBeam vertical guidance brackets contains 4 vertical guidance brackets and 2ml of SKF LGMT 2 general purpose grease in a syringe. We envisioned these brackets to function as linear sliders. Sometimes things do not go according to plan. Unfortunately the wear on a makerbeam is too high when the brackets are used under load. Instead these brackets can be used as brackets to guide vertical movement. With vertical movement the force on parts is not high. The brackets (4 pieces) come with a syringe filled with 2ml ball bearing grease. NOT to be used as horizontal load bearing linear slide structure. Usage as linear slide will lead to wear of the beams.