The Crawler Innovations Combination Cell Block features three - .250" holes, three - .375", and three - .500" holes that can be used for holding tools, building or rebuilding shocks, or whatever The large opening is 3.00" wide and is shaped to hold a cell phone or electronic device while the user listens to music, watches a video, or used as a stand to film from. Approximate size: 4.0" Height x 4.0" Width x 4.0" Depth