Review on Copper Silk 1.75mm Printer Filament: High-Quality Printing Material by Sean Davis

It's just a heating coil holder. It's not bad, but does a great job. As a spool holder, it has rollers on the bottom for low-friction feeding, but the placement of the filament holes is sub-optimal and creates drag. It really should have more holes so you can choose the optimal location for your printer. However, this is a very nice plastic reel seat. As a dryer, the temperature can reach 55°C and the timer can be set to 24 hours. Unfortunately, the air inside is about 20 degrees colder, so it doesn't get hot enough for the high-temperature filaments. There is no fan and moisture cannot come out, so the lid needs to be opened several times during drying to let the air out, otherwise the moisture will be absorbed back into the filament after the heater is turned off. It is recommended to add some desiccant to prevent this. The maximum heating time is 24 hours and must not remain switched on. The worst thing is that there is no hygrometer to show humidity. It would be nice to have this and have the unit heat up again when the level gets high. In general, this works quite well for PLA when used immediately after drying. It's not good for other species, although you can heat it for a long period of time. Of course, this depends on how much moisture your filament has. Instead, you can simply place the coil on your printer's heated bed at the right temperature. The improved dryer aims to retain heat better so it can perform better.