The helios apollo 22x85 ms observation binoculars are high quality waterproof nitrogen filled observation binoculars suitable for medium to long range terrestrial and astronomical observations featuring bak 4 prisms the binoculars have a multi coated optical system that allows for 92 light transmission and distortion free images built into the binoculars is a tripod mounting bush and threaded eyepiece units to allow for filters the long eye relief and fold down rubber eyecups make these b