For use with "03" sized L2K adapters. A split pip mold box removes the need for any lego bricks by providing a single piece mold box with 2 4x4 pip mold cavities. Just stick it on a base plate and you're ready to go! Using a split pip box cuts silicone usage by over 40% compared to 5x5 pip molds! Save time, hassle, and material usage with this valuable tool. Box material is PLA with thick walls designed to withstand repeated pressure cycles and silicone capillary forces.