The Steiner bluetooth adapter is for the M8x30r LRF Binocular 1535. It provides Bluetooth capability with compatible devices such as the Kestrel 5700 Elite weather meter with LINK. Steiner M-Series Military BT Adapter for M8x30r LRF 1535 Binocular 2627 transmits range data to the device to generate an accurate firing solution for the indicated distance. Waterproof up to 5m, this reliable adapter has a range of 5 meters. Its dimension is 34.5 x 26.7 x 17.2mm and weight is just 10 grams. Version 4.1 Steiner M-Series Military BT Adapter for M8x30r LRF 1535 2627