The sideview 10x21 is a classic design binocular porro prism with central focusing mechanism thanks to low weight and minimal dimensions the sideview 8x21 is perfect for constant long term use including hunting animal observation and bird watching landscape and urban observation vacations observation of sports events etc they are small enough to fit in a jacket pocket or car dashboard compartment the high 10x magnification allows you to have a closer detailed view of objects of inter