If you are new to vaping, you may not know that you can refill your cartomizers. Pre-filled carts are great for when you're just starting out, or even if you've used e-cigarettes for a few years. They are incredibly easy to use. Just take off the clear rubber caps and screw one on a battery. It's that simple! For people who are interested in learning all they can about e-cigs, carts, and e-liquid, or want to take their vaping to the next level, there are blank cartomizers. Blank cartomizers come in a few varieties to suit your particular preference. To use a blank cartomizer, you must remove the rubber caps and then fill it with 20-25 drops of e-liquid. There are many methods on how to fill a cartomizer, which you can read about here. Pre-filled cartomizers can also be refilled when they are empty. Like Vapor4Life's pre-filled carts, blank carts come in two types - CoolCarts and WOW carts. The purpose of each is the same - a filter to store e-liquid and vaporize it with the battery. They look the same on the outside, but their performance is different. Differences between CoolCarts and WOW carts CoolCart cartomizers hold a little more liquid than WOW carts, have a high resistance and run slightly cooler.  WOW cartomizers produce more vapor, and burn slightly warmer because of their lower resistance. Choose your favorite color! Blank CoolCarts and WOW carts come in several colors. Many vapers like to match their e-cig components. If they are using a red battery and red drip tip, they might want a red cartomizer to match. Having different colored carts can also help with organization. If you have four favorite vapes - banana, sour green apple, grape, and black licorice, you could use yellow, green, purple, and black to tell them apart. Blank CoolCarts are available in silver, white, pink, gold, royal blue, green, light blue, black, and red. Just this week we also added burgundy and brown based on customers' frequent request. Blank carts come in packs of 5. If you want some variety, two sampler packs are available. Sampler Pack #1 includes one of each of these colors: black, white, red, green, and royal blue. Sampler Pack #2 has gold, copper, pink, silver, and light blue. Blank WOW carts come in light brown, orange, faux filter, light green, purple, and red. WOW blank carts are also available in sampler packs with five different colors. Sampler Pack #1 has purple, white, red, and gold. Sampler Pack #2 has black, green, pink, yellow, and silver. For more a more technical discussion about cartomizers read  WOW or CoolCarts? written by guest blogger Morandir.