Fenix ALG-05 Pressure Switch Mount: Setup and Compatibility
By Fenix Flashlights | World Leader in Fenix® Sales | Fenix Lighting USA | Published: 2026-10-14
Category: How-to Guides
Learn how to install the Fenix ALG-05 pressure switch mount on a Picatinny rail and confirm AER-series compatibility before you buy.
Quick answer
The Fenix ALG-05 is a rail-mounted holder for Fenix AER-series tactical remote pressure switches, which are sold separately. Push it onto any standard Picatinny rail, then slide the AER switch body into the mount. Confirm you have an AER switch and a Picatinny rail before ordering, because the mount does not include the switch.
What the ALG-05 actually holds
The ALG-05 is a dedicated mount, not a universal clamp. Its body is aluminum alloy with a hard-anodized finish, and it is designed specifically for Fenix AER series tactical remote pressure switches. If you own a different brand of pressure switch, or a Fenix switch outside the AER series, the ALG-05 is not the right part and no adapter is listed. Treat the AER designation as the compatibility gate: find the model marking on your switch before you order.
Check the rail before you check the mount
The ALG-05 attaches to any standard Picatinny rail with a simple push, so the rail itself is the second compatibility gate. Picatinny and Weaver profiles look similar but differ in slot spacing, and a mount that is specified for Picatinny may not lock down correctly on a Weaver-only rail. If your rail is a proprietary or M-LOK-to-Picatinny adapter, verify the top section is a true Picatinny profile before installing.
Plan the switch position around your light
Where you place the ALG-05 depends on the light it controls. On a rifle setup with a Fenix TK16 V2.0, the dual tactical tail switches sit at the rear of the light, so the remote switch and its mount usually belong on the support-hand side of the rail, forward of the light body. Test the reach with an unloaded firearm and the light off before you tighten anything down. If the cable has to make a sharp bend or crosses the ejection port, move the mount rather than forcing the cable.
Helmet and headlamp setups use a different mount
If you are trying to move a headlamp onto a helmet, the ALG-05 is not the part you need. That job belongs to the Fenix ALG-04 Headlamp Helmet Mount, which attaches a headlamp to a FAST Ballistic Helmet with an NVG mount and is compatible with models including the HM60R, HM61R V2.0, HM65R, HM70R, HM71R, HM75R, HP30R V2.0, HP35R (Standard Edition only), and WH23R. Buying the ALG-05 for a headlamp is a common ordering mistake because both are small Fenix rail-style accessories.
ALG-05 installation steps
- Verify the switch is an AER series model: Locate the model marking on your Fenix remote pressure switch and confirm it is part of the AER series. The ALG-05 is built only for AER series switches. Checkpoint: if the switch is not AER series, stop here and do not order the mount.
- Confirm the rail is standard Picatinny: Inspect the mounting surface and confirm it is a true Picatinny profile, not a Weaver-only or proprietary rail. The ALG-05 pushes onto any standard Picatinny rail. Checkpoint: a Weaver-only rail is a stop sign, not a maybe.
- Push the mount onto the rail: Slide the ALG-05 onto the chosen rail slot with a simple push. Do not force it; if it will not seat, you are likely on the wrong rail profile or an obstructed slot. Checkpoint: the mount should sit flush before you add the switch.
- Seat the AER pressure switch in the mount: Slide the AER switch body into the ALG-05 until it is fully seated and the cable exits without a sharp bend. The mount creates a secure hold for the AER pressure switch. Checkpoint: a pinched or kinked cable means the mount position needs to move.
- Test reach and cable routing before tightening: With the firearm unloaded and the light off, check that your support hand reaches the switch pad naturally and that the cable clears moving parts. Adjust the mount position along the rail as needed. Checkpoint: if you have to stretch or shift your grip, relocate the mount.
- Do a final function check: Turn the light on and cycle through its modes using the remote switch. Confirm the switch activates reliably and the mount has not shifted on the rail. Common mistake: skipping the function check and discovering a loose mount at the range.
Product facts
- Fenix ALG-05 Pressure Switch Mount: The Fenix ALG-05 tactical remote pressure switch mount is designed for Fenix AER series tactical remote pressure switches, which must be purchased separately. Budget for the switch as a separate line item, and confirm your switch carries the AER designation before ordering the mount.
- Fenix ALG-05 Pressure Switch Mount: With a simple push, the mount attaches to any standard Picatinny rail, and the body is made of aluminum alloy with a hard-anodized finish. Installation needs no tools beyond the rail interface, and the metal body is built to survive rail contact rather than flex like a polymer clamp.
- Fenix TK16 V2.0 Tactical Flashlight: The Fenix TK16 V2.0 is a tactical flashlight with dual tactical tail switches, an IP68 dustproof and waterproof rating, and a stainless steel strike bezel with tungsten steel breaking tips. The tail-switch layout tells you where the remote switch and mount should sit on the rail, and the IP68 rating means the light itself is not the weak point in wet conditions.
- Fenix ALG-04 Headlamp Helmet Mount: The Fenix ALG-04 Headlamp Helmet Mount attaches a headlamp to a FAST Ballistic Helmet with an NVG mount and is compatible with HM60R, HM61R V2.0, HM65R, HM70R, HM71R, HM75R, HP30R V2.0, HP35R (Standard Edition only), and WH23R. If your goal is helmet-mounted lighting rather than a rail-mounted pressure switch, this is the correct accessory and the ALG-05 is not.
