Horizon hydrostik hydrofill pro horizon fch 020 this hydrofill pro from horizon is a hydrogen on demand desktop refuelling station designed for easy and automatic refilling of hydrostik pro metal hydride cartridges add pure water and connect to the ac grid dc solar or wind power solutions for a completely self sufficient renewable hydrogen system compatible with fuel cell power devices above 2w and up to 30w hydrofill pro is particularly suited for schools labs and technical learning