The biggest question I always get about the paddles in lipo lasers is how many diodes does it have. It's so funny because people think its about the number. This affects fluence and surface area only. Even if a paddle just had one diode and all 50 others were burned out, the penetration of it if it was a 635nm probe would penetrate deeper than having all 50 diodes and it be a higher wavelenght.
The fluence of the paddle must be balanced with the penetration of the diode. If just treating the chin or something not that deep, there is no reason to spend the extra money on paddles with 635nm probes.
The latest generation of paddles are made of fiberglass/plastic. They don't have the stainless steal surfaces like they did when they first came out.
The newer type also has more coolants. Some paddles have cooling system built into the paddles themselves. They have little fans that are built into the paddle that take out the heat so they have less down time.
Note: if dust or film gets on the diode, it can absorbe the radiation and can get hot anyway regardless of the cooling system. And the manufacture is not responsible and won't replace them usually as this was not their fought.
Before, the cooling systems were only in the motherboard inside the main box.
If going for cellulite reduction, this is the hardest to get rid fo with the laser. 660, according to almost everyone I talk to, does the worse. 635 does the best as it has the highet penetration.
Note: all the lasers go deep. I do not like when people use the word deep or depth. This is not the right word to use at all with lipo laser treatment. Penetration is what the goal is. 635 hits the target better to separate the free fatty acid to glycerol. It gives the signal to tell the fat to separate better than any other frequency.
Note: some paddles require gels, authors do not. If you don't want the ones that don't, let me know on my quiz. This is a problem for some.
If choosing a lipo laser with paddles, and you want to compare the differrent types, take my lipo laser quiz. I will pick out the one based on the answers you choose. Take the quiz here.