Light Labs' SNAPLOCK Microcentrifuge Tubes offer several features for benchtop work. The tubes have a click seal which insures closure during boiling and benchtop work. The larger cap makes for a bigger writing surface and ease of opening and closing. Researchers working with hundreds of microcentrifuge tubes every day love these tubes because they open easier than most tubes, yet stay closed during most applications. The SNAPLOCK Microcentrifuge tubes are RNase/DNase/Pyrogen free and packaged 1000 tubes/pack.