Nectar, one of the top mattress-in-a-box manufacturers, is running a great mattress promotion that you won't want to miss.

Through today, Nectar is offering up to $450 off select mattresses and bed frames. In addition, a free $399 accessory comes with any mattress purchase. Freebies include mattress protectors, sheet sets, and luxury pillows.

The company is best known for its big sale on Nectar mattresses, but these deals are outrageously good value. Compared to other high-quality mattress brands, you'll be hard-pressed to find better discounts and extras.

Nectar mattresses have a one-year trial period, with free shipping and returns. We also like that Nectar offers a "lifetime" warranty, guaranteeing the construction and materials of their products.

Nectar Memory Foam Mattresses (I think the Nectar Memory Foam mattresses are the best mattresses you can buy for comfort and value for money.

The company's Medium Firm mattress is one of the best mattresses you can buy, designed to relieve pressure and distribute your weight evenly with three layers of memory foam. If you want a cool bed to sleep on, this mattress' Tencel quilted cover provides breathability and should keep you cool so you don't wake up sweaty in the middle of the night.

Nectar's sale ends March 30 at 11 p.m. ET.