UL 1993-2021 STANDARD FOR SAFETYS Self-Ballasted Lamps and Lamp Adapters

A device that is constructed so that the alignment with the existing incandescent luminaire or portable luminaire requires an adjustment greater than +20 degrees shall be provided with adjustment of the device base with relation to the remainder of the device.
Examples include:
a) A rectangular-shaped device in which the device is to be parallel with existing walls when installed in a celling surface luminaire, and
b) A device incorporating a ballast compartment or lamp support arms that will in some cases have to be rotated more than 20 degrees to properly clear harps in portable luminaires.
A device intended to be used with a shade, glassware, or dlfuser shall be provided with that accessory.
A lamp adapter shall be provided with a positive means to retain the lamp or lamps in place in any possible mounting orientation, such as by clips, retaining springs, or the equialent. A securing means relying solely on the electrical contacts ol the lampholder des not meel this requirement.
When the integrity of the lamp securing means of a lamp adapter cannot be determined, the device lampholder shall comply with the minimum retention force values specified in ANSI C81.62, using the appropriate plug gauge specified in ANSI C81.63 for the intended lamp type.

LISUN following instruments fully meet UL 1993-2021 STANDARD FOR SAFETYS Self-Ballasted Lamps and Lamp Adapters

SMT-PA100A Articulated Test Probe of UL 1993 Figure 9.3