... device Product Name: Sales! Portable M40 gas detector (CO,H2S,O2,LEL) M40 SPECIFICATIONS: Size: 4.30" x 2.45" x ... secHydrogen Sulfide (H2S) 0-500 ppm 1 ppm 30 secOxygen (O2) 0-30% 0.1% 10 secCombustible (LEL) 0-100% LEL ... contact me. Thanks. Sales! Portable M40 gas detector (CO,H2S,O2,LEL)