The LGC2000 puck that came with my old 337 died a few yrs after getting it.....I "upgraded" to the 3000 which works fine(slightly quicker), just needed a blue to red cable. I believe those are the only 2 units that are plug and play....don't believe the 4000 will work with the 337. All this is available on ebay/out there for cheap. I"ve still got a 337 and a blue/red cable you could borrow if needed, but no puck(went with the Olympic). Good luck, Tom