The casing 2, wherein said grasping means comprise downwardly extending {TAIL ~ plate like projections} from {HEAD ~ said upper casing sidewalls} at the rear location of said upper casing 
The casing 2 , wherein said grasping means comprise downwardly extending { TAIL ~ plate like projections } from { HEAD ~ said upper casing sidewalls } at the rear location of said upper casing
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH