Is designed to enhance traction in ventilation and flue systems and protect from rain
Is made as per the calculations by the Central institute of aerodynamics
| D, mm | 2D, mm | A, mm | B, mm | Weight, kg |
| 100 | 200 | 170 | 120 | 0,79 |
| 110 | 220 | 180 | 132 | 0,95 |
| 115 | 230 | 185 | 138 | 1,03 |
| 120 | 240 | 190 | 144 | 1,12 |
| 125 | 250 | 195 | 150 | 1,21 |
| 130 | 260 | 200 | 156 | 1,3 |
| 135 | 270 | 205 | 162 | 1,39 |
| 140 | 280 | 210 | 168 | 1,49 |
| 150 | 300 | 220 | 180 | 1,7 |
| 160 | 320 | 230 | 192 | 1,92 |
| 180 | 360 | 250 | 216 | 2,41 |
| 200 | 400 | 270 | 240 | 2,95 |
| 220 | 440 | 290 | 264 | 3,54 |
| 230 | 460 | 300 | 276 | 3,86 |
| 250 | 500 | 320 | 300 | 4,53 |
| 300 | 600 | 370 | 360 | 6,46 |