Worth the hassle, but needs high temperature color gels
These are awesome. Its basically a metal dish that goes inside your par 64, where the bulb normally goes, with an adapter in the center of it, one side plugs into your par 64', the other side fits a much smaller, much cheaper, but eqaully powerfull GE A1 bulb, that just plugs right in. Regular par 64 bulbs cost £35 - 40 euro - $50 each, but these smaller GE A1 bulbs that fit this adapter cost you only £10 - 12 euro - $15, and are just as bright, last just as long, and are usually available locally everywhere. But you must have High Temperature lighting gels, (known as HT gels) for them. Regular lighting gels go brown and crispy with these bulbs, you have to get high temperature lighting gels from Ebay (£10 each, one gel does up to 4 lights), and also High Temperature diffuser gels too, which are frosted lighting gels, that make the light a little less harsh for the performers to work under. I find 2 x 500 watt lights, up on a lighting T-bar looks amazing for our pub band, giving a full, wide, professional spread, not like cheap, dim, small spreadding LED ones, and aren't hot or blinding at all, are plenty powerfull enough, and the two, cover the whole band fully and evenly with colored light.