

RAM Mounts Double Ball Drill-Down Mount with Diamond Plate (RAM-B-138U) is a complete kit for lightweight devices: a 63.5 mm round ball base with AMPS pattern to screw to a dashboard, console, desk or wall, a medium B-size double socket arm (95 mm overall) and a diamond ball base with 2-hole AMPS pattern for the device holder. The patented rubber ball-and-socket system allows near-infinite adjustment and dampens shock and vibration to protect the device.
📦 What's in the box – RAM-B-138U
- Round plate with ball – Ø 63.5 mm, 4-hole AMPS + 3-hole 120°, B-size ball (RAM-B-202U)
- Double socket arm – B-size, medium, 95 mm overall, 76 mm socket to socket (RAM-B-201U)
- Diamond ball base – 62 × 33 mm, 2-hole AMPS, B-size ball (RAM-B-238U)
💡 To get started, you might also consider a device holder with the 2-hole AMPS (diamond) pattern, such as the universal small-device holder with diamond pattern.
Key Features
- Complete kit – base, B-size double socket arm and device-side plate in one package
- Adjustable at both ends – medium arm, 95 mm overall; one knob locks both ball joints
- Two plate types – round 63.5 mm AMPS base for the surface, 62 × 33 mm diamond plate (2-hole AMPS) for the holder
- Shock and vibration damping – the patented rubber ball-and-socket system cushions the mounted device
- Load rating – up to 2 lb (0.9 kg) in standard use and 1 lb (0.45 kg) in heavy-duty use; ideal for phones, GPS units, scanners and small tablets
- Built for harsh conditions – powder-coated marine-grade aluminium, backed by RAM's lifetime warranty
Compatibility
- Device holders with the 2-hole AMPS pattern (48.6 mm hole spacing)
- Flat surfaces such as dashboards, consoles, panels and walls (drill-down)
- All RAM B-size (1") ball bases and device holders with a B-size ball
Technical Specifications
| Part Number | RAM-B-138U |
|---|---|
| Product Type | Mounting kit, B-size |
| Connection | B-size (1" / 25.4 mm) ball; round 63.5 mm plate (4-hole AMPS 30 × 38 mm, 3-hole 120° Ø 46 mm) + diamond plate 62 × 33 mm (2-hole AMPS 48.6 mm) |
| Arm Length | 95 mm (3.73") overall; 76 mm (3") socket to socket |
| Load Capacity | 2 lb (0.9 kg) standard use; 1 lb (0.45 kg) heavy-duty use |
| Dimensions | Overall height 127 mm (5") |
| Material | Powder-coated marine-grade aluminium |
| Weight | 0.24 kg (0.52 lb) |
| Warranty | Lifetime warranty (RAM Mounts) |
| In the Box | Round plate with ball, double socket arm, diamond ball base |
You will find matching cradles, holders and more RAM mounting parts in our Mobile Terminal Accessories collection. Planning a vehicle or forklift installation, or ordering for a whole fleet? Contact us for project support and volume pricing.
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