Back to: Gap Inspection Gauge Gap Inspection Gauge Product Code: 22624 Gap Inspection Gauge, Swagelok compression fitting inspection gauge, 1/4", 3/8", 1/2" compression fittings Price £43.00 Description Confirm that fittings are sufficiently tightened. For use with 1/4″, 3/8″, 1/2″ Swagelok® fittings. For Swagelok® fittings in new installations only.