Z-RAM support says the linked 0.2 L ON/OFF HPA bottle combination can be filled while it remains mounted on the marker. That answer concerns this bottle-and-regulator arrangement; it is not blanket approval for every marker, conversion or filling setup.
Which product does that answer concern?
The linked 0.2 L combination includes the bottle and an 1100 PSI regulator with an integrated ON/OFF slide valve. The separate ON/OFF regulator is another purchase: the regulator itself, not the complete bottle combination.
What fitting does the pump need?
Z-RAM's reply describes a standard PCP airgun hose. It does not name the customer's pump model or give an exact pump-side connector specification, so that fitting remains unconfirmed. Before choosing a hose or adapter, have the pump model, its connector and the exact bottle/regulator combination checked together.
The separate regulator's description says it is threaded-ASA compatible. That is not a specification for the unknown pump-side connection. A familiar hose label is also not enough to establish the equipment's pressure rating: the Empire tank manufacturer manual, for example, requires properly rated fill fittings and assemblies.
The complete combination and its regulator-only alternative

0.2 LITER bottle incl 1100 PSI On/Off Slide Valve Air Tank Regulator 3000 PSI Umarex T4E FSC Valken Pistelle X-68- Option 1100 PSI output + 0.2 L bottle
The actual 0.2 L bottle combination covered by the support answer. The current option includes an 1100 PSI regulator and integrated ON/OFF slide valve.
View the complete combination
NEW! On/Off Slide Valve Air Tank Regulator 3000 PSI 1100 PSI Output Umarex T4E FSC Valken Pistelle X-68 - Option 1100 PSI
The separately offered 1100 PSI ON/OFF regulator, with built-in slide valve and listed threaded-ASA compatibility. Do not read the regulator-only offer as a complete bottle or a pump connector specification.
View the regulator onlyGeneral context: a paintball-field fill station
This independent introduction explains a typical paintball-field fill-station connection and refers to the tank's fill nipple. It does not establish approval for a particular Z-RAM assembly or an unspecified pump.
▶ Play on YouTubeHow To Fill Your Paintball Tank
Channel: How To Play Paintball
General Z-RAM context: model families
For separate Z-RAM shop context, this short introduces the Umarex T4E and FSC/TCP model families covered by the parts range.
▶ Play on YouTubeFind the Best Umarex T4E Parts at Z-Ram.net . HDR68 TR50 HDP50 TS68 Pepperball First Strike
Channel: Z-RAM
Important Legal Notice
Laws and regulations governing the purchase, possession, installation, modification, and use of the products described on this page vary by country, state, and local jurisdiction and may change. Before purchasing, installing, modifying, or using any product, you are responsible for confirming that it is permitted in your location and for your intended purpose. Product availability or delivery does not mean that purchase, possession, installation, modification, or use is lawful in your jurisdiction. Z-RAM does not provide legal advice, and the information on this page must not be treated as legal advice. If you are unsure, contact the competent local authority or a qualified legal professional.
