SACRAMENTALS - EXPLANATION BELOW
Sacramentals are material objects, things or actions (sacramentalia) set apart or blessed by the Roman Catholic Church to manifest the respect due to the Sacraments, and so to excite good thoughts and to increase devotion, and through these movements of the heart to remit venial sin, according to the council of Trent (Session XXII, 15).
Sacramentals excite pious dispositions, by means of which the faithful may obtain grace. It is not the sacramental itself that gives grace, but the devotion, love of God, or sorrow for sin that it inspires, and the prayers of the Church that render sacramentals efficacious against evil.
Only the Sacraments give grace of themselves and are always fruitful when the faithful place no spiritual obstacles in the way. The Sacraments were instituted by Jesus Christ; but not all of the sacramentals were instituted by the Church.