CLAIM The ornamental design for a sight glass, as shown and described.
FIG. 1 is a left front perspective view of a sight glass showing my new design, the bottom is a mirror image of the top;
FIG. 2 is a front elevational view thereof, the undisclosed rear is unornamented and not part of the claimed design; and,
FIG. 3 is a right side elevational view thereof, the left side is a mirror image.
* * * * *
Field of SearchOPTICAL ARTICLE NOT ELSEWHERE SPECIFIED
Lens or objective
Magnifying or reducing glass
MIRROR, FRAME, PICTURE MOUNT, OR EASEL TYPE SUPPORT
Fastener or coupling (38)
Clamping or gripping (40)
Having structure to secure picture (e.g., tab, catch, slot, etc.)
Knockdown or set-up type
Connector having aperture to receive fastener
Having storage for nondisplayed picture
OPTICAL APERTURE OR TUBE, OR TRANSPARENT CLOSURE