The apadravya(ap-ah-drav-ya), like the ampallang, is a piercing that passes through the glans. While the ampallang passes horizontally through the glans, the apadravya passes vertically through the glans from top to bottom, almost always placed centrally and passing through the urethra. Off-center apadravyas are also possible, wherein the piercing is deliberately offset, yet usually still passes through the urethra. The piercing is often done on a slightly forward angle to the hips.
Sometimes the apadravya is referred to as happydravya because it is said that having sex with a person who has this piercing is highly pleasurable.
An apadravya is usually done in one session, though sometimes in two; the first creating a Prince Albert and the second (after healing) completing the apadravya. Straight barbells are the usual jewelry for apadravya piercings. The barbell must be long enough to accommodate erection and initial swelling. The apadravya is usually pierced with a slightly longer barbell than required for a fully healed piercing, and downsizing the length can be required. The barbell can also end with the second ball inside the urethra, providing that the urethral meatus is big enough, however, most men have too small a urethral meatus for that option. The diameter of the initial barbell is usually 2.0 or 2.4 mm (12 or 10 gauge).
The healing time of an apadravya piercing can vary greatly depending on healing rate and diligence of the aftercare. Usually one can have intercourse with a condom after about one month, but normally it takes at least three months for the piercing to fully heal. After initial healing the piercing can be gradually stretched and larger jewelry can be inserted, reaching sizes above 10 mm in diameter. The piercing should be done in three steps. First a catheter is inserted. Then the needle up from the bottom into the catheter to ensure straightness and that its actually going through the urethra. Then the catheter is removed and the needle pushed up to the top of the glans.
Because it passes through the most sensitive part of the penis, the procedure is among the most painful of male genital piercings. However, once healed, the apadravya is usually very pleasurable to wear, as it stimulates the penile tissues internally. It is generally thought of as the most pleasurable for female sexual partners, since the top of the piercing is positioned such that it contacts the G-spot in vaginal intercourse. It is also pleasurable for same-sex partners, since the bottom of the piercing is positioned such that it contacts the prostate in anal intercourse.
The apadravya piercing is mentioned in the Kama Sutra "In the hole made in the lingam a man may put Apadravyas of various forms, such as the 'round', the 'round on one side', the 'wooden mortar', the 'flower', the 'armlet', the 'bone of the heron', the 'goad of the elephant', the 'collection of eight balls', the 'lock of hair', the 'place where four roads meet', and other things named according to their forms and means of using them. All these Apadravyas should be rough on the outside according to their requirements." 
Variations include the shaft apadravya which pierces the shaft (uncommon, and not performed by many piercers); the magic cross which is a combination of the apadravya and the ampallang; and the apadydoe. If the penis has been subincised or meatotomized, the piercing is called a halfadravya.
- Apadravya at the BME Encyclopedia
- (chapter 2 verse 11) The Kama Sutra of Vatsyayana, tr. by Richard Burton, , at sacred-texts.com CHAPTER II OF THE WAYS OF EXCITING DESIRE, AND MISCELLANEOUS EXPERIMENTS, AND RECIPES