Clifford
When you say Lewyt Electronic Upright, are you referring to their Big Wheel canister model that has the electric hose & power brush? If so, you can go to your local vac shop & ask for "Hoover SR" bags for the Hoover Duros canister. You should also be able to find these bags on online retailers & Walmart may also stock them too, as they sold that particular vacuum. They will fit your Lewyt perfectly. If you want HEPA Cloth bags, the "Hoover Type S" bags for the Hoover Futura/Hoover Windtunnel canisters will also work & fit fine as well.
However, if you are referring to one of the uprights, & it is a soft bag machine & the paper bag has a paper tube that attaches with a spring to a plastic tube at the bottom of the bag, you will want to buy "Eureka F&G" bags for your Lewyt Upright. However, make sure that you buy the "Filteraire" version if you buy Genuine Eureka bags, or "micro filtration" version if you buy generic bags....it's been my experience in the past that plain paper bags clog way too quickly & you have to throw out the bags with little dirt in them. If you want to use HEPA Cloth bags in your Lewyt Upright, then there is a conversion kit for Sanitaire & Eureka uprights that allow their machines to use the "ST" HEPA Cloth style bags, & unless there's something drastically different about your Lewyt Upright it should be compatible with your machine.
Hope this helps you out & welcome to Vacuumland.
Rob