Twin extra long to replace split king expensive brand. Bass is very heavysturdy. Easy install there’s only legs to screw on after choosing which height you want, and the foot bar to keep the mattress from shifting. The mattress is heavy, dense, and comfortable. Firm but cushioned. Remote control has easy to view buttons, three speeds of vibration for head and foot, light under the bed along with US B ports for charging phones, full range of mobility and elevation for the head and the feet. Highly recommend this alternative to the expensive store front brand. We were worried about there being an odor of chemicals, but there were no unpleasant odors. Good nights sleep.