As a general rule, if you were to draw a 4" or 5" round circle, and then draw a striaght line 3/4" off the bottom, you could see if you need the 4" or 5" housing by comparing your video camera to the drawing.

 

Note:  Most modern camcorders will fit the 5" housing perfectly.  We offer custom housings for most applications.  The 4" housing is used for the newer ultra small camcorders.  If you e-mail us your model number, we will be glad to check fittment for you and make recommendations.