Sectional comes in three pieces; Sofa with Corner Wedge, One Arm Loveseat and one Armless Chair.  They attach together with brackets.  To make the secitonal shown, it must come with all three peieces, which are included in the price; extra armless chairs can be added to make one side longer, priced separately.
 
The side with the One Arm Loveseat can be extended longer by adding Armless Chairs.  The side with the Sofa with Corner Wedge cannot be made longer.  This sectional is reversible, meaning the One Arm Loveseat can be on either side.  For a smaller version visit. https://www.winterportfurniture.com/product-page/alenya-sectional
 
Looking at the front of the sectional, if you want the One Arm Loveseat on the left, you would order LAF Loveseat (55), if you want it on the Right, you would order the RAF Loveseat (56).  The corresponding Sofa is listed below.
LAF Loveseat (55) & RAF Sofa (67)
RAF Loveseat (56) & LAF Sofa (66)
 
Item Description:
Merging a decidedly clean profile with cozy comfort, this sectinoal is high style made for real living. Neatly tailored box cushions and crisp, track arms beautifully enhance the aesthetic, while a fresh hued microfiber upholstery simply works. Pair of script pillows are a posh touch.
 
Item Features:
Corner-blocked frame
Attached back and loose seat cushions
High-resiliency foam cushions wrapped in thick poly fiber
3 decorative pillows included
Pillows with soft polyfill
Polyester/nylon upholstery
Linen/viscose pillows
Exposed feet with faux wood finish