Visaton sl87wpm mylar coned waterproof fullrange speaker visaton sl87wpm 4 ohm the visaton sl87wpm 4omega is a waterproof 8cm 33 inch full range speaker it has a transparent plastic cone and rubber sealing ring this speaker has a high mean sound pressure level and compact design and has been optimised for both voice and signal output typical applications include use as a control speaker for electronic devices and outdoor sound reinforcement systems visaton sl87wpm 4 ohm mylar coned wa