Johann Baptist Cramer's Op. 71, '25 New & Characteristic Diversions,' are études designed to develop pianistic technique and musicality. They explore various technical challenges in a characteristic and engaging manner.
Requires excellent finger dexterity and control for rapid passages.
25 New & Characteristic Diversions (Op.71) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 9.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
25 New & Characteristic Diversions (Op.71) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.