First year I went to Zimbabwe I used 10x42 Swarovski SLC's for the next 7 trips I went up to 10x50 Swarovski SLC's for better early morn late evening use. While they are heavy I have worn them for everystep I have taken on safari and that's a lot of steps. Most reliable Binoculars i've ever had. Used a fine old pair of Bausch & Lomb 9x35's till someone wanted them more than me and relieved me of them. Replaced them with a pair of 8x30 Swarovski SLC's but missed the higher power glasses.