A kneeler is a cushion (also called a tuffet, hassock, genuflexorium, or genuflectorium) or a piece of furniture used for resting in a kneeling position during Christian prayer.
[1] In many churches, pews are equipped with kneelers in front of the seating bench so members of the congregation can kneel on them instead of the floor.
In a few other situations, such as confessionals and areas in front of an altar, kneelers for kneeling during prayer or sacraments may also be used.
Traditionally, altar rails often have built-in knee cushions to facilitate reception of Holy Communion while kneeling.
A kneeler is also a part of the prie-dieu prayer desk.