UL Listed (UL Recognized Safety Container for butane fuel). RVR has 12 spots (3 scores each) on the seaming port of the Dome (Top). When the pressure is over the standard level, the scores open to release gas while rupturing the dome, and lowering the inner pressure to prevent an explosion. RVR is a Back-Up Safety Technology Protecting an Unused Can from Over-Pressuring Automatically reseals when removed from stove. Notched Collar provides easier alignment in portable gas burners! Compatible with a diverse variety of camp stoves. Each can lasts approximately 2 to 8 hours of burn time compact,lightweight & affordable with a weight of only 8 oz per cartridge. Stronger fuel source than propane UL Listed (UL Recognized Safety Container for butane fuel). RVR has 12 spots (3 scores each) on the seaming port of the Dome (Top). When the pressure is over the standard level, the scores open to release gas while rupturing the dome, and lowering the inner pressure to prevent an explosion. RVR is a Back-Up Safety Technology Protecting an Unused Can from Over-Pressuring