L&B Optima. Very accurate, small will fit inside your helmet. It has 3 high speed audible settings for free fall and 3 low speed settings for under canopy. So for example you can have an audible set at 4500, 3000, and 2000 and also have another set of audibles for 1000, 600 and 300 that will go off under canopy. Not to mention the best customer service in the industry.