4" Lens for Screw-On Sight Glass

Special extra thick lens for screw-on sight glass made of heat resistant borosilicate glass.

This lense is destined for mounting as sight glass on one of our 4 inch screw-on sight glass elements.

Please be aware that although borosilicate glass is very robust, it can have asperities and air entrapment in the glass, as well as asperities by chipping at the edges due to the difficult processing. This is not a product flaw, but a characteristic caused by production. Please handle items made of borosilicate glass with utmost care, do not clamp them too tight, and do not put them down onto hard surfaces! All glasses are carefully inspected by us before delivery and singled out if deviant. We can not accept subsequent complaints.