RAM® Ball Base with 5/16"-18 Post - B Size

Part#:RAM-B-239U UPC:793442916632

RAM® Ball Base with 5/16"-18 Post - B Size

Part#:RAM-B-239U UPC:793442916632

Ball Size

B Size C Size

Size Guide

Size	Ball Diameter	Max Load	Best For
A	0.56″ (14.3 mm)	0.5 lb (0.2 kg)	Action cameras and other ultra-light devices
B	1″ (25.4 mm)	2 lbs (0.9 kg)	Phones, GPS units, and small tablets — the most common size
C	1.5″ (38.1 mm)	4 lbs (1.8 kg)	Large tablets, fish finders, and rougher rides
D	2.25″ (57.2 mm)	6 lbs (2.7 kg)	Rugged tablets, laptops, and heavy equipment
E	3.38″ (85.9 mm)	15 lbs (6.8 kg)	Large displays and demanding aviation or industrial use

*Approximate capacity for a standard ball with a mid-length arm. Shorter arms and steel-reinforced posts increase real-world capacity.

Reading part numbers

The letter after RAM tells you the ball size: RAM-B-166 uses a 1″ B ball, while RAM-D-201 uses a 2.25″ D ball. C size parts are the exception and carry no letter, so RAM-201U is a C size arm.

199 kr

Incl. VAT

On request

This item is available on request. Leave your email and/or phone number and we’ll get back to you — it may already be on order or ready to assemble from parts in stock. If we need to source it specially, lead time is typically 6–8 weeks.

Looking for a faster option? Alternatives such as components or a different arm length are often available — contact us and we’ll help you find the right fit.