I.  Insulators under tension

A.  Standoffs and wireholders
B.  Ribbed radio strains

1.  Symmetrical shape

a.  All ribs are the same size

i.  Ribs go all around the insulator
ii.  Smooth channel along the side

b.  Ribs of different sizes
c.  Diamond shaped ribs

2.  Assymmetrical shape

"The Rocket"/Christmas Tree radio strain

C.  Smooth sided radio strains with no permanently affixed metal caps

1.  Rods (cylinders)
2.  Rectangular

IN-86

D.  Long-rod strains with metal caps on both ends

E.  Special purpose insulators

1.  Center insulators
2.  Transposition insulators

F.  Modern polymers

A.  Spools
B.  Guy Strains

1.  Across the top wire groove
2.  Through the insulating body's wire groove
3.  Within the insulating material

Composition stains

C.  Hewletts

1.  Hog livers
2.  Extended skirts on one side
3.  Extended skirt on both side

D.  Modern types (glass and porcelain)
E.  Smooth underside
F.  J-D Spider connectors and heavy porcelain bodies

1.  4.1" wide (milk chocolate)
2.  4.3" wide (dark chocolate)
3.  6" wide

a.  Slopes inward quickly (blue, milk chocolate)
b.  Doesn't slope inward until almost the top (dark chocolate)

4.  6.5" wide (blue, brown umber)
5.  11" wide (blue, brown)

2 styles

G.  Bell shaped and fog types
H.  Spiral grooved tops
I.  Complex suspensions

1.  Heating element included
2.  Lightning arrestor included

H.  Suspension systems

1.  Fred Locke