as the housing 1 and as it follows base support 19 and extends the outer boundary of the cover 10 at the first outer boundary 13 found on either side of the strip first outer boundary 13 bulges out past the outer dimensions of first portion 20 and middle portion 40 established by tapered edges 4 and parallel edges 6 respectively similarly second outer lip 12 surrounds throughhole 7 and extends the outer boundary of the cover 10 at second outer boundary 14 also found on either side of the strip second outer boundary 14 bulges out past the outer dimensions of second portion 30 and middle portion 40 established by rounded corners 5 and parallel edges 6 respectively the lips 11 and 12 and outer boundaries 13 and 14 have generally the same shape as the cross sectional shape of housing 1 and throughhole 7 respectively as shown in fig1 first outer lip 11 is generally oval shaped and first outer boundary 13 is generally arcuate as the cross sectional shape of housing 1 is substantially an oval second outer lip 12 is generally oval shaped and second outer boundary 14 is generally arcuate as the cross sectional shape of throughhole 7 is substantially an oval first portion 20 first outer lip 11 middle portion 40 second outer lip 12 and second portion 30 are all coplanar and past of the top surface 15 housing 1 is bounded on all sides by a wall 16 as shown in fig2 said wall 16 protruding from the top surface 15 the walls 16 terminate at the housing cap 17 the cap 17 is the first element of the cover 10 to extend through throughhole 7 when the cover 10 is in use fig1 also.