The size and weight of the testicles vary greatly from age to age. For example, during the neonatal period, it is about 10x5x6 (length x width x thickness) mm3 and weighs about 0.2g (unilateral); at age 1, it is about 16x7x9 mm3 and weighs about 0.7g; at age 8 to 10, it is about 16×7.5×10.5mm3 and weighs about 0.8g; at age 14, it is about 21x10x12 mm3 and weighs about 1.5g. When the testicles are touched normally, they appear slightly larger than the above figures because of the subcutaneous tissue of the scrotal skin separating them from the outside, but these figures are not absolute and are only for reference.