Hugyfot Housing for Nikon D90 7 User manual4. Opening and closing the housingThe HUGYFOT Nikon D90 housing is opened and closed by means of 2 built-incountersunk bolts.This guarantees the safest way of clo-sing. Only with the right key you canopen and close the housing. A curi-ous buddy cannot open the housingby accident. Herewith we exclude theunwanted opening of the housing. Toseal the housing, the socket screw keyis inserted into the countersunk boltand then turned until the shells aresqueezed to one another. Stop turning the key when resistance increasessignificantly. Further turning the screws hasn’t got any sense and can onlydamage the thread. At a depth of 6 meters the hydrostatic pressure takesover and keeps all the o-rings under pressure. Always check the tension onthe bolts before diving if the housing wasn’t opened in between two dives.First maintenance command:The screws, and more specific the tread, must be kept very clean at all times.The main o-ring merely lies in the o-ring groove. It can be removed by blow-ing it out with compressed air, by using a credit card or by rubbing two piecesof paper towards each other against the o-ring so the o-ring pops out of hisgroove. Never use a metal object or any other hard material: by doing this youcan DAMAGE the O-ring and the groove.Second maintenance command:Whenever the o-ring is dirty or misted up, it must be removed from itsgroove (see first command) and cleaned up with soap (do not use corrosiveor chemical degreasers). Afterwards clean it with clear water.O-rings have to be dried up with a clean cloth (do not squeeze) or by air.Grease the O-rings (except the main red o-ring) by using HUGYFOT grease.Pull the o-ring gently through your fingers without stretching it! O-ringgrooves, housing and shell edges have to be cleaned with a clean cloth.