ok , like other reviewer have say the suction be not that great ; it hold well for a little while but it have to be on a absolutely clean and dry surface . if there be the slightest bit of moisture , grease , food residue etc. on the surface , or if anything get spill around it and get around where the suction cup meet the surface , it will not hold - so it be not really very effective on high chair and stroller tray . a determine toddler -lrb- like mine -rrb- can quite easily find the little release tab on the base and you know how they be , once they have figure something out once they keep on do it over and over and over and over and over ... however have say all that the rubber base do stop they slide about even if they be not adhering to whatever you be try to stick they to and they be much more stable than regular plastic bowl . they also have quite high side compare to normal bowl which make it that much harder for tiny learn spoon coordination to flick the food over the side . they come with very tight fitting , secure lid which be good for take along or , if you be go through that oh-so-fun fussy eating stage you can just seal the untouched meal and toss it in the fridge until next time . it be also nice to have the versatility of three different size for the variety of meal -lrb- and leftovers -rrb- small child seem to generate . all in all I be quite pleased with these & glad I buy they even though they turn out to be not so useful in the intended way .