A system comprising a gas detector (100, 402, 701, 802) and a gas detector calibration cap (200, 300, 404, 703, 804) for calibrating said gas detector (100, 402, 701, 802), wherein the gas detector (100, 402, 701, 802) comprises: a gas detector housing, comprising: a front shell (102, 812) comprising one or more exhaust opening (108,512,612) and a groove (106, 808) on an edge of the front shell (102, 812); and a back shell (104, 814) connected to the front shell (102, 812) comprising a first slot (120, 506, 606) on a first side of the back shell (104, 814), a second slot (120, 508, 608) on a second side of the back shell (108, 814); and one or more sensors or filters disposed within the gas detector housing; and wherein the gas detector calibration cap (200, 300, 404, 703, 804) comprises: a cap body (202, 302), comprising a nozzle (208, 308, 410, 510, 610) disposed on the cap body (202, 302) and an exhaust opening (108, 210, 310, 512, 612); a first cap wing (204, 304) connected to the cap body (202, 302), comprising a first opening and a first overhang extending through the first opening; a second cap wing (206, 306) connected to the cap body (202, 302), comprising: a second opening; a second overhang (214, 314) extending through the second opening; and an extended strip (216, 316) attached to an end of the second cap wing (206, 306), characterized in that the extended strip (216, 316) comprises a protrusion (220, 320, 806) configured for opening the front shell (102, 812) of the gas detector (100, 402, 701, 802) by inserting said protrusion (220, 320, 806) in said groove (106, 808) on the edge of the front shell (102, 812) of the gas detector (100, 402, 701, 802) and by applying force on said extended strip (216, 316). wherein the gas detector (100, 402, 701, 802) comprises: a gas detector housing, comprising: a front shell (102, 812) comprising one or more exhaust opening (108,512,612) and a groove (106, 808) on an edge of the front shell (102, 812); and a back shell (104, 814) connected to the front shell (102, 812) comprising a first slot (120, 506, 606) on a first side of the back shell (104, 814), a second slot (120, 508, 608) on a second side of the back shell (108, 814); and one or more sensors or filters disposed within the gas detector housing; and a front shell (102, 812) comprising one or more exhaust opening (108,512,612) and a groove (106, 808) on an edge of the front shell (102, 812); and a back shell (104, 814) connected to the front shell (102, 812) comprising a first slot (120, 506, 606) on a first side of the back shell (104, 814), a second slot (120, 508, 608) on a second side of the back shell (108, 814); wherein the gas detector calibration cap (200, 300, 404, 703, 804) comprises: a cap body (202, 302), comprising a nozzle (208, 308, 410, 510, 610) disposed on the cap body (202, 302) and an exhaust opening (108, 210, 310, 512, 612); a first cap wing (204, 304) connected to the cap body (202, 302), comprising a first opening and a first overhang extending through the first opening; a second cap wing (206, 306) connected to the cap body (202, 302), comprising: a second opening; a second overhang (214, 314) extending through the second opening; and an extended strip (216, 316) attached to an end of the second cap wing (206, 306), characterized in that the extended strip (216, 316) comprises a protrusion (220, 320, 806) configured for opening the front shell (102, 812) of the gas detector (100, 402, 701, 802) by inserting said protrusion (220, 320, 806) in said groove (106, 808) on the edge of the front shell (102, 812) of the gas detector (100, 402, 701, 802) and by applying force on said extended strip (216, 316). a cap body (202, 302), comprising a nozzle (208, 308, 410, 510, 610) disposed on the cap body (202, 302) and an exhaust opening (108, 210, 310, 512, 612); a first cap wing (204, 304) connected to the cap body (202, 302), comprising a first opening and a first overhang extending through the first opening; a second cap wing (206, 306) connected to the cap body (202, 302), comprising: a second opening; a second overhang (214, 314) extending through the second opening; and an extended strip (216, 316) attached to an end of the second cap wing (206, 306), characterized in that the extended strip (216, 316) comprises a protrusion (220, 320, 806) configured for opening the front shell (102, 812) of the gas detector (100, 402, 701, 802) by inserting said protrusion (220, 320, 806) in said groove (106, 808) on the edge of the front shell (102, 812) of the gas detector (100, 402, 701, 802) and by applying force on said extended strip (216, 316). a second opening; a second overhang (214, 314) extending through the second opening; and an extended strip (216, 316) attached to an end of the second cap wing (206, 306), characterized in that the extended strip (216, 316) comprises a protrusion (220, 320, 806) configured for opening the front shell (102, 812) of the gas detector (100, 402, 701, 802) by inserting said protrusion (220, 320, 806) in said groove (106, 808) on the edge of the front shell (102, 812) of the gas detector (100, 402, 701, 802) and by applying force on said extended strip (216, 316).