Ulfhednar Thumb Timer and Mount 4x4x3. These Thumb Timers were originally designed for the swiming sport. We made a mount for rifle making it very vissible and accessable when moving in a stage. Easy to read BES display with large numbers. Counts up. One button only "On" "Start" "Zero". Waterproof Specifications for Ulfhednar Thumb Timer and Mount: Manufacturer: Ulfhednar Height: 4 in Length: 4 Weight: 50 g Last Chance: Yes Package Contents: Ulfhednar Thumb Timer and Mount Ulfhednar UH922: Thumb Timer and Mount 4x4x3