When the Lambert Shopping Trolley Handle flashes a smiley face it means that one product is a better purchase than another.

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hen health-conscious people hit the grocery aisle, they spend countless minutes poring over nutrition labels to decide which products are the best to take home. A new collaboration out of Britain called the Change Project aims to dramatically shave that time down, using a smart grocery-cart attachment to help consumers make faster and more-informed buying decisions. Here, a brief guide to the proposed technology: 

How does the gadget work?
The Lambet Shopping Trolley Handle is equipped with a barcode sensor and can clip onto any cart. It uses a 16-LED multicolor display to give would-be buyers a quick idea of the products they're buying, including allergen information and calories. "One color pattern might indicate that a product is organic, and another might tell you if it's local" by flashing the words low, medium, or high, to indicate the food miles the product traveled to get to your store, says Ariel Schwartz at Fast Co. Exist. Users can compare two competing products with the scanner, which tells you which item is the better buy with a smiley face, and steers you away from less healthy options with a neutral or frowny face. The system is "appealing because of its simplicity," says Walter Frick at BostInno.

But don't smartphone apps already do the same thing?
Yes, apps like GoodGuide and Redlaser can help you compare products. "But people generally have their hands full with food when shopping, so it's difficult to whip out a cell phone every time you want to examine a product," says Schwartz. The Trolley Handle, on the other hand, hooks right onto your cart.

Does it really help shoppers make better decisions? 
Apparently so. A recent study of the Lambet Shopping Trolley Handle revealed it helped "influence food choices" for a select group of U.K. shoppers, says Jenny Wilson at Smart Planet. "Nearly 75 percent of shoppers using the handle were more likely to choose products with lower food miles than they did when they shopped without it." 

Will the Trolley Handle make it over to the U.S.?
That's what its inventors are hoping , but as of right now there's no timeline for a release. In any case, says Frick, "this judgey shopping cart is a step in the right direction" to help consumers make more conscientious purchases. 

Sources: BostInno, Discovery, Fast Co. Exist, Smart Planet