When I've looked at the bicycle brands at Walmart, I've found Bel products. Although I've never used this brand, I prefer several others because some carry lifetime warranties, Cateye. Although some of their accessories are sometimes pricey, I can assure you, they stand behind their product line. They've replaced more than one of my lights when asked. In most cases, it is I who damaged the light, not their quality of workmanship. I believe these are still available from this online store. Bikes, Cycling Clothing, Bike Parts & Cycling Gear: Bike Discounts & Deals from Nashbar
Here is another online source: Find Bikes, Cycling Clothing, Bike Parts & Bike Shoes Or Your Local Bike Store at Performance.
Although I've listed two online sources, I still try to buy at a local bicycle shop, provided they have what I want.