Irritrol's TW-PROG Portable Decoder Programmer comes from the Rain Master Twice Series. This programmer is battery operated, and can be used for any Two-Wire Decoders. Irritrol has made their name as a brand by selling and marketing exclusively to the professional installer, as a result their products are geared to be dependable and durable. Irrirtrol is now making their products available to you through our website. If you are looking for a product line that will last year in and year out, Irritrol is the brand for you.