This is part of the series of handheld electronic games released by Mattel in the late 70's. It is an original vintage game, not one of the recent reissues. If you are buying with the intention of actually playing the game I would recommend the originals over the reissues. The button action and the display screen both work a lot better on the originals.
The game console is in VERY GOOD condition. All buttons, switches and sounds work as they should. Battery cover is present and battery compartment is clean. The backing is beginning to peel away from the battery terminal but it still makes a good connection. You will probably want to repair that though.... One other item of note - there is what appears to be a small cigarette burn near the arrow keys. Otherwise cosmetically it's in good shape. I would grade it 6 on a 10 scale (see condition guide below).
Box is in POOR-GOOD condition overall. As you can see it is missing part of the side panel. Otherwise decent shape with crushing but no bad stains or writing. All the flaps are in place. I would grade it 2-3 on a 10 scale (see condition guide below).
MINT (10): I will only give this grade to brand new, unused items. NEAR MINT (9): Shows virtually no use. Seldom if ever played. Perhaps some very light scuffing to the back of the console. Packing materials, instructions and other paperwork will show almost no signs of handling. Boxes will have only the slightest hint of shelf wear. EXCELLENT (7-8): The game has seen some use but it was obviously well taken care of. Console will have more noticable scuffing, maybe light wear visible on the screen or in the button area. Paperwork may have some light handling creases. Packing materials may have a light stain or small chips but will be intact and free cracking. Boxes will have light rubbing to the artwork, perhaps some minor creasing, small tears on the flaps or a small stain. VERY GOOD (5-6): The game was not especially well cared for but it still has faired pretty well. Some obvious scuffing from play but all labels intact and readable. Perhaps a very minor chip on the edge. Paperwork will have some handling creases and may be lightly stained or have some writing. Original packing materials may be damaged but will be intact. Box will have some rubbing, light staining, creasing, small tears, minor writing and/or a few pieces of tape. Might have a missing flap. No major structural damage and artwork will still be generally attractive. GOOD (3-4): Obviously no care was taken with the game but it is still playable as is. Console will show heavy use but will not be seriously damaged in any way. May have a few burnt out LED but is still playable as is. Paperwork will have heavy handling wear and may be torn and taped back together. Box may have staining, writing, heavy creases, tears and/or other structural damage but it will be intact and still usable. POOR (1-2): Only suitable to fill a space in your collection. Game may be seriously damaged or inoperable. Paperwork will be badly torn. Box will have major damage.