There are many features on the JP041 that are present on more professional models:

Fully ribbed construction and double spine on B & C keys provides additional strength

Underslung octave mechanism also improves instrument reliability

High F# and Front F keys

Floating plate design for the little finger (left hand) cluster

Adjustable thumb rest allows a more natural and comfortable hand position

Sling ring also provides the opportunity to make the instrument even lighter with the use of a provided sling or harness