prefocus cap
prefocus base
cap which enables the luminous element to be brought into a specified position relative to the cap during manufacture of the electric lamp so that reproducible positioning can be assured when the electric lamp is inserted in a suitable lampholder
Note 1 to entry: This entry was numbered 845-08-20 in IEC 60050-845:1987.
Note 2 to entry: This entry was numbered 17-978 and 17-977 in CIE S 017:2011.