The head is very lightweight as you can see in the photo. This means you carry less weight on you and it doesn't strain the machine - less wear and tear. Since it doesn't strain it - you also have lower consumption, and it performs better compared to a heavier one, and it doesn't use up a lot of line, which means you don't have much loss. Also, with some lines - where the line is wound around a spool - and at the end it doesn't return but takes the shape of the spool - with this head you won't have an issue because it fits in a standard position. The bottom part is plastic, which is why it is lightweight. Of course, it wears out faster compared to one that has an aluminum bottom, but you can't have it all. The aluminum would also be heavier. It's better to spend money again after some time to get another such head, rather than spending it on fuel/wear and tear of the machine, etc. - due to heavier heads... Lastly, I should mention that it screws and unscrews perfectly with the trimmer's spark plug wrench.

5 stars without having tried it yet (so I may come back if something changes), because it seems to be of good quality and a well-known (Italian) brand. It is the model 50909007 with aluminum on the top and hard plastic on the bottom. The disadvantage is that the plastic, no matter how good its quality is, will eventually wear out, so maybe then I will upgrade to the fully aluminum 50909006, which has a relatively comparable cost (15 euros instead of 11). On the other hand, the latter requires periodic lubrication according to the instructions, while the 50909007 does not.

The installation of the trimmer line is easy: simply unscrew the cap on the bottom and place 1 to 4 pieces of trimmer line, bending them in the middle. The Tecomec recommends 1 piece (thus 2 ends) for trimmers smaller than 33cc, while most (up to 8 ends) for those above 33cc. The actual placement itself is a 3-second process per piece of trimmer line, as it wedges very easily, especially if it is square. If I remember correctly, it officially supports trimmer line of maximum thickness 4mm, but it wouldn't surprise me if it could handle 4.5mm as well.

Unfortunately, the package does not include a key and Tecomec requires a 24mm tubular wrench to tighten/loosen the bottom plastic part. I don't know if there is a 24mm socket wrench, while most trimmers come with keys up to 21mm. So an extra purchase of a tubular wrench will be needed (5-20 euros for a 24mm one). Be careful that the key externally should not be cylindrical but should have angles (male, that is) to fit into the female socket of the head. The top part has 4-5 available slots with the appropriate one to be placed according to the diameter of the shaft below the angle.

Overall, it seems to be a quality and durable construction, with minimal maintenance requirements and easy installation. The only obvious disadvantages are the lack of a key in the package and the plastic bottom. I will come back after using it.

Very good quality head, takes two or four double pieces of trimmer line and tightens very easily with the wrench. An important advantage that this specific head has is that it almost never cuts the trimmer line as it goes in double.

One of the best heads I have tried. With 4 double pieces of nylon string (a total of 8 ends), it trims the ground without straining the trimmer. It is also the easiest to change the nylon string. It separates into 2 parts, one remains screwed onto the head and by unscrewing the other, you can change the nylon string.