Conversion rail systems offer you the flexibility of transforming your existing crib into a toddler bed or full-size bed. If you have purchased a convertible crib already, you might need to purchase a conversion rail kit separately so it’s best to check. Kits vary in their performance. Some are designed to turn a crib into a toddler bed, others into a regular bed and some offer the option of guard rails. So it is important that you find the right kit for both your crib and your needs. It’s also ideal to purchase your conversion kit at the same time as your crib to ensure that you will have the kit when you need it.