P20 ONCEADAY Sunfilter is simply not like any other product. Riemann P20 OnceaDay Sunfilter is a well tried and tested product to protect from sunburn while allowing a gentle, slow golden tan. It is a unique product as it needs to be applied only once a day 15 minutes before exposure to the sun. Theres no need to reapply the product so you can simply get on with enjoying yourself. Easytofollow instructions are provided with each bottle. Riemann P20 OnceaDay Sunfilter provides high sun protection factor 20 and is still 90 effective after swimming. P20 is remarkably good value Once a day application means a little goes a long way and therefore it is more economical than other sun preparations which need to be reapplied regularly during the day.