This is the Highland Mini Tech Pressure Gauge and Kit Option Features: Available as gauge only, or in kit form The gauge will thread directly into a regulator&';s first stage HP port With a complete kit, it will thread onto the end of a HP hose Kit includes gauge, in-line adapter and airspool 0 to 5000 psi (0 to 350 bar) Gauge and airspool include viton o-rings Highland by XS Scuba Mini Tech Pressure Gauge is a great gauge for technical diving, deep diving and overhead environment diving activities. Gauge is small and compact measuring only 1.1 (2.8 cm) in diameter, .88" (2.2 cm) tick and can be mounted directly into a high pressure (HP) port of a first stage regulator or with the adapter and included air spool on the end of a high pressure hose. Gauge is especially advantageous when used with stage bottles, decompression and safety stop bottles where a full size pressure gauge is not necessary. "