Do Hi-T MH Bulbs have a built in ballast?

HI-T 400 WATT TUBULAR MERCURY BALLAST METAL HALIDE LAMP


http://www.deslamps.co.uk/hit-400-watt-tubular-mercury-ballast-metal-halide-lamp-p-3188.html


it says "these lamps are designed to fit into e40/standard mercury fittings"

i have a ballast but my other grow light is using it, id rather just buy one of these, and stick it into an e40 lamp holder straight to the mains.

like this one.

http://cgi.ebay.co.uk/Envirolite-la...14&_trkparms=72:1296|66:2|65:12|39:1|240:1318

No you need a ballast for that I think. From what my google search found, E40 (40mm) is the base size. Pretty similar to the US 39mm diameter E39 Mogul Screw fitting. I think there just telling you what fitting it has and what ballast it will work with. My ballast will do either Mercury Vapor or Metal Halide(I think most MH set ups will too. I am not too sure on this though, I know an HPS bulb won't work with an MH ballast) .