1000w MH Bulb

Hey, Sorry for the noob question, Just wanted to check if this was the right bulb before I order it..
I have a Xtrasun 1000w Convertible Ballast 120v..
And i need a New Metal Halide Bulb.. I was Looking at Theses on 1000bulbs.com and needed to know if i was looking at the right list thanks..
http://www.1000bulbs.com/1000-Watt-M...uced-Envelope/
Theres also theses
http://www.1000bulbs.com/1000-Watt-Metal-Halide-BT56/
Some are BT56 And some are BT37?

yup all those are 1000mh but you might want to see if your reflector can handle a bt-57 and as far as how good they are you get what you pay for eye hortulux is the goods

Thats what im trying to Find out? Witch one i need..

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