GROCO Sight Glass Fits ARG-1000. This Rear Sight Glass by GROCO works with a Float Level Sensor (label included in package with pump) it is installed from the rear with a stainless steel stem that aligns with the float in the bilge. The Groco ARG-1003 Sight Glass has the ability to view fluid levels in both high and low galling ranges. Comes in a pair the Groco ARG-1003 Sight Glass Fits ARG-1000 is a great addition to your ARG-1000 Float Level Sensor / Reservoir. Specifications for GROCO ARG-1003 Sight Glass Fits ARG-1000: Manufacturer: GROCO Color: Black Package Contents: GROCO ARG-1003 Sight Glass Fits ARG-1000 GROCO ARG-1003: Sight Glass Fits ARG-1000 ARG-1003