The power of a lens is +4D. Find the focal length of

power 4d4D History - Check 4D number past winning history since 1985. 4D Number Pemutation. mBox, iBox, i-Perm Source . Date From. Date To. DisclaimerPower dsp 4ch value_acoustics VA 15.4D Daya output: 4x 1500watt @8ohm, 4x 2000watt @4ohm Bridge 2x 3800watt @8ohm Input: analog, aes ebu, dante Output