This is RAM's shortest B-size double socket arm — the low-profile option when you want minimal distance and flex between the base and the device, for example in a compact cab where a longer arm would put the device too far into your field of view or too close to a control. It uses the same B-size (1") ball and socket mechanism as the medium and long arms in this family, just packaged into a much more compact body.

What's in the bag

In the bag: the two-piece aluminum arm body and the stainless-steel knob-and-bolt assembly. One real difference from its medium and long siblings, confirmed on RAM's own product documentation: this specific short arm does NOT include the internal pin spring — its body is too short to fit one. That just means you open the sockets by hand instead of them springing open on their own; the finished connection tightens and holds exactly the same way. Overall length is 2.42" (61.5 mm) with a 1.75" (44.5 mm) socket-to-socket span.

Made of powder-coated, marine-grade aluminum. A composite version (RAP-B-201U-A) exists with identical dimensions if you prefer that material.

How RAM's modular system works

Every RAM product on this page is part of the same modular system used across RAM's entire catalog. Once you understand how it fits together, every other RAM accessory we sell will make sense too.

1. A base — clamps, bolts, or straps onto the vehicle (a rail, a roll bar, a dash, a windshield, or a device's own housing).
2. An arm — connects two RAM balls together. It can be locked at any angle, so once mounted you can tilt, rotate, and reposition the device freely, then lock it firmly in place by hand.
3. A cradle or holder — grips the specific device (tablet, phone, GPS unit, camera).

The ball size determines what it can carry. RAM uses five ball sizes, each rated for a different weight/duty class:

Rule of thumb: if the mount will live somewhere that's frequently jostled, vibrated, or under constant load — an off-road vehicle like a tractor, ATV or UTV — RAM recommends stepping up to the larger ball size (C rather than B) for extra stability, even if a lighter mount would technically hold the device's weight.

No tools required, on purpose. RAM arms are designed to be tightened by hand only — there's no official torque spec, because the ball-and-socket joint is meant to be adjustable in the field without a wrench. If hand-tightening doesn't hold your device firmly, that's usually a sign the ball size is undersized for the device — sizing up solves it, rather than over-tightening.

Aluminum or composite — both are built for the outdoors. RAM mounts are made from marine-grade aluminum or high-strength composite, interchangeably depending on the product; both carry a lifetime warranty and similar weight ratings. Aluminum's powder-coat finish handles rough vibration and shock slightly better; composite skips the paint entirely, so it has nothing to chip and is often preferred in high-corrosion or salt-air environments. Neither choice is worse — it's a trade-off between finish and environment.

Inside a double socket arm

A RAM double socket arm is the piece that does the actual adjusting in the system described above. Two cupped "socket" halves clamp around a ball on each end; a single knob and bolt running through the middle squeezes both sockets shut at once. On most double socket arms, a small spring inside pushes the sockets open again as soon as you loosen the knob, so the arm falls open by itself and you don't have to pry it apart to reposition a ball — a detail RAM's own documentation confirms, and one you won't usually see spelled out on a spec sheet.

That spring is also where the arms in this family differ in a way that's easy to miss: RAM's own product documentation notes that the shortest B-size arm (RAM-B-201U-A) does NOT include the pin spring the medium and long arms have — its very short body doesn't leave room for one. In practice this only means you open that particular arm by hand rather than it springing open on its own; it locks and holds exactly the same way once tightened.

The knob itself is a stainless-steel hex bolt with a black finish running through a nylon or composite handle — confirmed on RAM's own documentation for this arm family. If it's ever disassembled, the correct order to rebuild it is: bolt through the hex hole in one socket casting, the second socket casting, then the plastic washer, the metal washer, and finally the knob. Every arm in this family also has a composite sibling (for example RAP-B-201U-A instead of RAM-B-201U-A) that uses high-strength composite instead of marine-grade aluminum — same dimensions and same ball size, just a different material trade-off (see the materials section above).

Which length do you need?

All three lengths use the same B-size (1") ball and carry the same weight rating — 2 lbs (0.9 kg) standard use, 1 lb (0.45 kg) heavy-duty use. Length is purely about reach and clearance: go short in a tight cab where you need the device close to the base, go long when you need to clear a dashboard edge, a steering column, or reach around an obstruction.

Specifications

Completes a mount with

This is a connector only. Pair it with a B-size base and a cradle for your device to complete the mount — this short arm works well for a compact keypad or a phone you want held close rather than out on a long reach. Need the tougher C size instead? A B-size arm will not attach to a C-size ball — see the C-size arms on this page instead.

• RAM ATV/Side By Side Rail Ball Base (B Size, Zinc) — the matching B-size base
• FJD Bluetooth Keypad (Easy Control)
• RAM Ball Adapter for John Deere (C Size — needs a C-size arm)
• RAM ATV/Side By Side Rail Ball Base (C Size — needs a C-size arm)

Frequently asked questions