The Vixen Alpina binoculars feel so comfortable in your hands that you won't want to put them down! Weighing only 665g and with a comfortable, moulded rubber grip you can take them with you anywhere. Roof Prism Design. Field of View = 6.1 Waterproof Close focus down to 2m Phase coated roof prism binoculars designed with a long eye relief and multi-coated optics.