Please note – in addition to the trimmer, you will need to purchase a laser measure, easily sourced from online stores. Choose a simple, low-cost laser such as the Bosch PLR 30 C, or a fully featured product with Excel linking, like the Leica DISTO D1 or D2. Trimming sheets are usually in Excel format and can be obtained from your wing manufacturer. Simply enter the measurements and the sheet will tell you if your wing is too fast or too slow, with an indication of what changes to make. You will also need access to a weight (such as a 5 kg water ballast bag).