evad:It takes an Uk sl4. The only LED replacement I have found is from MAL Lighting (they call it an HLD). They're 80 bucks from tech-blue.com .
Got the MAL bulb out of Sweden @ dyk for $56USD including shipping. I pit them in PT's amnd they are O.K. Have since pd the big bucks for a Heser, and it blows the others away.