Instruct: Classify Amazon reviews into positive or negative sentiment
Query: O ring schmo ring

this thing sucks, you shouldn't have to mod a product in order to make it work as it was originally intended. modding is for making things work BETTER than they were intended.the lip doesn't seal securely when you push it on the tire valve stem.plus it goes thru 1 set of batteries per year, which is too often i find myself with dead batteries when i need it. i buy duracell or energizer batteries for it.there is no on/off switch. i suspect this is why it goes thru batteries more often than it really should. it probably stays on for a while and then automatically shuts itself off after a predetermined set of time.would be better if it had a real on/off switch.DO NOT BE FOOLED.the power button you see on the product is for the *weak* 10 cent LED flash light, NOT for the tire pressure gauge itself.