All 302 Series Detectors are normally open devices and are available in either 135°F (57°C) or 194°F (90°C) ratings. Each unit is constructed with a high expansion .040 anodized aluminum （氧化铝）sensing shell and fine silver contacts which are hermetically sealed to ensure reliable operation. Electrical Rating （额定电功率）6-28 VDC, 1 amp. (all models)

302-135- Interior, Vertical Mounting static Temperature 135°F Maximum Spacing - UL 50' x 50'
302-194 - Interior, Vertical Mounting static Temperature 194°F Maximum Spacing - UL 50' x 50'

302-ET-135 - All Weather, Vertical Mounting static Temperature 135°F Maximum Spacing - UL 50' x 50'
302-All Weather, Vertical Mounting static Temperature 194°F Maximum Spacing - UL 50' x 50'
302-AW-135 - Moisture and Dust Proof, Vertical Mounting static Temperature 135°F Maximum Spacing - UL 50' x 50'
302-AW-194 - Moisture and Dust Proof, Vertical Mounting static Temperature 194°F Maximum Spacing - UL 50' x 50'

302-EPM-135 - Explosion Proof Screw Base, Vertical Mounting static Temperature 135°F Maximum Spacing - UL 40' x 40'
302-EPM-194Explosion Proof Screw Base, Vertical Mounting static Temperature 194°F Maximum Spacing - UL 40' x 40'
302-ET-194