JM Series pure hydrogen generator, uses water electrolysis with alkaline(KOH) technology. We produce JM-300 with H2 flow 0--300ml/min, JM-500 H2 flow 0--500ml/min and JM-1000 machine: H2 flow at 0--1000ml/min. Smart outlook, outside is iron metal case, strong to use years. Inside gas system is unique, KOH liquid will never return. Have hydrogen output flow rate digital play, easy to view H2 output flow. Hydrogen output pressure display. Water level display with mark. Machine normal working light display etc. Machine is very easy and durable to be used for 5--10 years. Easy maintenance. Only need to add distilled water for daily using. It is economic and traditional technology to produce pure hydrogen gas. Widely been used in variously brands GC instruments in the world.