RDL No. 1 refers to RDL Babyface Astringent Solution #1, a skin toner used for maintenance to achieve a smoother, lighter, and more radiant complexion, often after using stronger RDL #2 or #3 products. It helps minimize tanning, freckles, and dark spots, and contains ingredients like Melawhite, Arbutin, and Salicylic Acid for skin brightening and exfoliation, but requires sun protection (sunblock) and moisturization at night for safe, effective use. 
What it is
A mild astringent/toner for facial skin care.
Designed for skin brightening, fading blemishes, and maintaining clear skin. 
Key ingredients
Melawhite/Arbutin/Magnesium Ascorbyl Phosphate: Skin brighteners.