The Coleman Mosquito Deleto Refill can be bought offline from places like Amazon and eBay. Unfortunately, Coleman does not make this product or any of the refills anymore. There are two different parts that you can purchase. The first you will need is the adhesive trap refill. They are priced around $40. There may be local stores that carry this, but online is the best place to start. Many places even offer free shipping.
The second part that you will need is the Coleman mosquito deleto octenol refill. This is used for attracting the mosquitoes to the Coleman unit, then the adhesive trap captures and kills them. They are usually sold in monthly supplies. You will need to place the unit not near people, so the mosquitos are drawn away from you.
This is one of the best units ever made to get rid of mosquitoes. Make sure you get the replacement cartridges needed in order to keep the unit working for you year round.
Coleman makes many other great products, however it is very unfortunate they do not make the mosquito deleto or refills for the unit. Many places still sell parts and supplies for the mosquito deleto system. There are even people who make replacement parts for the unit that are not made by Coleman. These parts work just as well as the originals.