The article presents the problematic of openwork disc brooches, with a rhomboidal plate in the centre, and mounts (for headgear, such as a "cap", or a belt) of identical shape discovered in the area of the West Balt cultural circle. Until recently, it seemed that such artefacts had not been popular in the region in question. Archival research and new excavations have provided information on many new examples of such artefacts. In total, three to six brooches with rhomboidal openwork and, which is extremely interesting, as many as five or six similarly shaped mounts are known from the territory of the West Balt cultural circle. All the openwork fibulae presented in the catalogue resemble disc brooches from the Roman provinces. They are similar to type 24c distinguished by M. Feugère 1985:335-336, fig. 24C). Finds of such brooches were concentrated in central-eastern Gaul, Burgundy and western Switzerland. Determining the chronology of the discussed openwork brooches in the West Balt cultural circle is not easy. The brooch from Mojtyny (Fig. 1: 1) should be dated to phases B2-C1b. The specimen from Černâhovsk, grave 30), (Fig. 1: 9) should most probably be assigned to phase B2, although there is a slight possibility that the assemblage dates to phase B2/C1-C1a. The Petino brooch (Fig. 2:19) should be dated to phases B2a - B2/C1-C1a, with phase B2b being the most probable. The context of the discovery of the brooches from Prussia (Fig. 2:18) and East Prussia (?) (Fig.3:2) is not known, therefore, they cannot be included in the considerations about the dating of such finds. The openwork mounts can be studied in more detail, as the assemblages in which they were discovered contained many chronologically sensitive artefacts. The earliest dating specimen is the one from Parussnoe (Fig. 9:1), which comes from phase B2a. The mount found at Kovrovo, grave 30 (Fig. 4:2), is "younger" than the one discovered at Parussnoe and should probably be connected with phase B2b. The chronology of the mount discovered at Putilovo (Fig. 5:5) can only be determined broadly to the entire phase B2 as well as the artefact found at Bol’šoe Isakovo (Fig. 7:1), whose interpretation is uncertain. Some of the openwork fibulae described in the catalogue are certainly imports from the Roman provinces, as indicated by the clear form similarity. However, it is also probable that some of them were manufactured in local workshops and are imitations of provincial artefacts. The Petino fibula (Fig. 2: 19) fully corresponds to the forms known from the Roman Empire. It seems that the specimen from Černâhovsk (Fig. 1:9) is also an import, although it lacks the characteristic concentric circles in the centre. There are doubts in regard to the specimen found in former Prussia (Fig. 2: 18) - its spring construction and ornamentation resemble accessories manufactured in local workshops. The brooches from Mojtyny (Fig. 1: 1) and former East Prussia (Fig. 3:2) do not find faithful analogies in the material known from the provinces, however, parallel fibulae are found in the area of the Tarand Grave Culture. The openwork mounts collected in the catalogue are almost identical to the openwork brooches typical of the Roman provinces. Thus, they may have been imported from the Roman Empire. Nevertheless, at least some may also have been manufactured locally as imitations of the fibulae known from the provinces. The presence of openwork brooches and mounts in the graves of the Dollkeim-Kovrovo Culture dating to phase B2 is another argument for a local fashion involving openwork accessories having emerged on the Samland Peninsula at that time. This trend had spread from the Dollkeim-Kovrovo Culture to the Lithuanian coast, where numerous openwork accessories, e.g., pin heads and brooches, appeared a little later, in the Late Roman Period.