The colored ring on the 5020 series leadholders came in a variety of colors as indicated in the Alvin Color Guide above.

All of the Alvin 5020 series (and 7020 series, not shown) leadholders were manufactured in Germany by the Fedra company. I don't believe Fedra ever sold products directly in the United States, but they manufactured a number of items that were sold under other names including these leadholders and the Alvin 5000 and 5555 lead pointers. Alvin also used similar model numbers to Fedra's.

Box of 12 Alvin 5020 series leadholders.

This pencil is part of the set shown below which included Alvin's 5555 Pocket Lead Pointer and a glass tube of lead. Notice that guaranteed is misspelled twice in the Guarantee.

The 5021 C differs from the 5021 S in only the colored pushbutton shank and the correspondingly colored lead that came supplied in them.

 

This model 5021 is missing the original pocket clip.

This pencil has a unique grip pattern. The barrel is scored on only two opposing facets because the pencil would be held with the flat of the lead against a straight edge and, of course, never needed to be rotated to maintain even lead wear.

	Alvin Constructor packaging circa 1950s. package courtesy Robert Rogers collection