Comparison Kobra +3 CC4 vs Kobra +1 SS6

Shredder security level according to DIN 66399. For its designation, the letter P (from Paper) and a number from 1 to 7 are used.

This indicator determines how well the destruction is carried out, how difficult it will be to recover a document or media passed through the device. The DIN 66399 standard provides seven security levels with the simplest numbering from the lowest to the highest: P-1, P-2, P-3, P-4, P-5, P-6, P-7. These levels apply to both paper and other media, however, shredders are used primarily for paper documents, this option will be discussed here; see "Shred items" for similar information on other materials.

— P-1. The paper is cut into stripes with a width of less than 12 mm or into pieces with an area of up to 2000 mm². A basic level that allows you to easily restore a destroyed document; designed for the utilization of documents that do not contain classified information.

— P-2. The paper is cut into stripes less than 6 mm wide or into pieces up to 800 mm². From a practical point of view, it has no fundamental differences from level P1 — except that the shredder waste bin fills up not so quickly due to the smaller size of the fragments.

— P-3. The paper is cut into stripes...with a width of less than 2 mm or into fragments with an area of up to 320 mm². It is impossible to restore a document destroyed in this way manually, although this can be done using special technical equipment.

— P-4. The paper is cut into pieces with a width of less than 6 mm and an area of less than 160 mm². This level is considered perhaps the most optimal for "considerate" materials, which do not require the maximum security levels — for example, everyday business documents like financial statements. Recovery from level P4 processing is extremely difficult even with special equipment (although possible), while the shredders themselves are relatively simple and inexpensive. In addition, they can easily provide destroying paper clips and staples.

— P-5. The paper is cut into pieces with a width of less than 2 mm and an area of less than 30 mm². This level is ready for business documents of strategic importance, such as long-term plans.

— P-6. The paper is cut into pieces with a width of less than 1 mm and an area of less than 10 mm². After such processing, the restoration of the document becomes almost impossible.

— P-7. The maximum level of security: the paper is cut into pieces with a width of less than 1 mm and an area of less than 5 mm². Such shredders are very expensive, and besides, they do not have much performant. Therefore, it makes sense to use them for documents of special national importance and other materials of similar importance.

It is also worth noting that the security level affects the speed of filling the shredder waste bin. The smaller the pieces of paper, the denser they fit into the basket and more time it takes to fill it with the same volume.

Way the shredder's knives move during the operation.

- Stripe cut. Alternative names "straight" or "lengthwise" are also met. This type models have one row of knives, and during operation they cut the material into stripes. The rate of protection against recovery (reliability of information destruction) is somewhat lower than in shredders with cross-cutting, however, stripe cutting provides significantly higher speed and productivity. Therefore, such models are recommended primarily for cases where the ability to work with large volumes of materials is most important.

- Cross-cut. For cross-cutting two rows of knives are used, which are arranged at an angle to each other; due to this, the shredded material is not cut into stripes, but into separate pieces of a certain size, depending on the security level (see above). In general, the rate of security is much higher than stripe cutting, and if safety and reliability of destruction are the most important, so you should pay attention to such models. The other advantage is that small pieces ensure that the waste bin is filled more densely, and it will have to be emptied much less frequently. Cons that worth noting are the relatively low speed and higher cost rate.

The largest possible size of the fragments that come out from the shredder after being processed. However, it's told about fragments only in the case of using cross-cutting; for stripe cut models (see “Cut Style”), this item indicates the largest width of the stripes. The size of the fragments is directly related to the security level provided by the shredder; see the relevant paragraph above for details.

The speed that processed unit moves through the shredding mechanism during utilization. Accordingly, the higher this indicator, the higher the productivity of the shredder and the more units it is able to shred in a certain time. Knowing the volume of the documents to be shredded, you can easily determine the time required for batch utilization: for example, with a speed of 45 mm/s, one load of standard A4 sheets (length 297 mm) will require 297/45=6.6 s.

However, it should be taken into account that this parameter is usually indicated for paper of a certain density — 80 g/m² (standard office paper) or even 70 g/m², depending on the manufacturer. When working with thicker paper, as well as other materials (see "Shredding Items"), the shredding rate may be significantly lower than stated.

The number of sheets that the shredder is capable of processing at one time — in other words, the largest size of a stack of sheets that can be loaded into the device. Most modern shredders can handle multiple sheets; up to 5 pcs at a time is considered a very limited indicator, up to 10 pcs — a small one, 11 – 15 pcs can be called an average value, 16 – 20 pcs — quite good, and in the most powerful models this figure exceeds 20 pcs.

Note that this parameter is given for paper of a certain grammage (and, accordingly, thickness). At the same time, the East European standard for office paper is a grammage of 80 g/m², and in many European countries thinner paper is used with a grammage of 70 g/m², and it is for it that the capacity of many shredders is indicated. Therefore, if this moment is not specified in the specs, it is best to load the shredder not up to limit values, making a margin of 1 sheet per 8 sheets of capacity — 1 sheet with a stack thickness of up to 8 sheets, 2 sheets with a stack thickness of 8 to 16 sheets, etc. However, other conditions for density may be specified in the user manual.

Also note that the number of sheets per load is determined by manufacturers based on the results of tests under perfect conditions — in the absence of staples on paper, with low humidity,...optimal voltage in the mains, perfect sharpening of knives, etc. In fact, any deviation from these indicators affect some decrease in efficiency.