Harken Black Magic Air Blocks - Aluminium Footblock with Lockoff (57mm, 75mm)
Use footblocks to redirect lines on the deck. Footblocks with lock-offs temporarily secure sheets. Either metric or imperial flathead fasteners may be used for mounting and are not exposed. Sideplates and sheaves Hard Lube-anodised for maximum UV protection and a smooth surface. Center cage keeps Torlon® roller bearings separated and parallel to reduce friction.
| Part Number | HKN-3221 | HKN-3236 |
| Sheave Ø (mm) | 57 mm | 75 mm |
| Length (mm) | 84 mm | 111 mm |
| Weight (g) | 154 g | 320 g |
| Maximum line Ø (mm) | 12 mm | 14 mm |
| Fasteners (mm) | 6 FH mm | 8 FH mm |
| Maximum working load (kg) | 1134 kg | 2380 kg |
| Breaking load (kg) | 2268 kg | 4762 kg |
| Height (mm) | 25 mm | 32 mm |
| Number of fasteners | 4 | 4 |
| A (mm) | 9.5 mm | 11.5 mm |
| B (mm) | 22.5 mm | 28.5 mm |
| C (mm) | 51.5 mm | 70.5 mm |
| D (mm) | 16 mm | 21 mm |
| E (mm) | 59 mm | 77 mm |
| F (mm) | 84 mm | 110 mm |
| G (mm) | 13 mm | 17 mm |
