Luster Leaf 1601 Rapitest Test Kit for Soil pH, Nitrogen, Phosphorous and Potash, 1 Pack It?s vital to know the existing pH, Nitrogen (N), Phosphorous (P) and Potash (K) levels in garden soil. The rapitest Soil Test Kit continues to be the standard for home soil testing. The kit includes all components needed to for (40) tests: (10) each for pH, Nitrogen, Phosphorus and Potash. The patented color comparator system allows for easy color comparisons versus a typical printed color chart. Extensive, yet simple, instructions are included along with recommendations for over 400 plants. Test results allow the gardener the amend and fertilize appropriately, ensuring the best possible results Features Quick, at home results for Soil pH, Nitrogen, Phosphrous and Potash Innovative and inexpensive soil test kit features an easy-to-use capsule system and patented color comparators Contains all components needed for 40 tests. 10 for each of pH, N, P and K Simple, detailed instructions included. Great for beginners and experienced gardeners alike. Soil pH preference list for over 450 plants included USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.