Better and brighter, Fujinon's Polaris 7x50 FMTR-SX binoculars deliver light transmissions above 95 percent and 23mm eye relief. The housings are made of light alloy for maximum durability with minimal weight, while the housings are dry nitrogen purged and sealed. Rubber armored models provide extra impact protection and are easier to grip when wet. Such models also include Fujinon's unique attached lens caps. Unique Light Transmission Fujinon’s unique EBC coating allows 95 percent of light to pass through the binoculars great for low-light performance. DurabilityIt features a robust body with an airtight, waterproof structure, enabling use in harsh conditions from -20-degree to +50-degree-Celsius. Designed with Long Eye ReliefLong eye relief design with a maximum length of 23mm. Eye relief refers to the distance between one’s eyes and the eyepiece that still allows one to view the entire field of vision. Long Eye Relief binoculars allow one to see right up to the edge of the field of vision even while wearing glasses, with this distance at over 15 mm.