The M1
| Hook | Dry type, 10 to18 |
| Thread | Black |
| Body | Goose feather dyed yellow |
| Tails | Red cock hackle fibers |
| Wings | Dark CDC fibres, extending well toward the bend of the hook. |
| Hackle | Light red cock hackle, short fibers. |
| Creator | Marcel Langhendries |
| Use | Classical caddis imitation. Use it in the evening or out of the heavy mayfly hatches. |