Part 50
50.br1) Eye piece, brass, part 51 | 50.br2) Eye piece, brass, wider slot, part 50 | 50.br3 Eye piece with boss, brass, part 50a | 50.br) With lateral hole in boss, renumbered 50 in 1945 |
| 50.zn Zinc plated | 50.br4.',300,302,'white')) Brass, without lateral hole (Meccanoids) | 50.bk) Black plastic slide, brass pummel, no lateral hole |
