A combination pH buffer kit with 5 x 20ml sachets of pH 4.01 and 5 x 20ml sachet of pH 7.01 with certificate of analysis. Simply tear off the top and insert pH electrode or tester into the sachet. Who can purchase restricted items from us?Findel Education will only sell to Academic Customers and will deliver only to the school address for educational purposes. To order please contact our customer service team on 03451 202055. The National Counter Terrorism Security Office seeks to restrict the supply of certain chemicals. Philip Harris have a duty to control the supply for these chemicals and any private individual attempting to purchase these chemicals may have their details passed to the police in their area. If you require waste disposal within the UK please contact All Waste Matters Ltd on info@allwastematters.co.uk for a quote.