This Vintage 60/70s Britool 2RB Double-Ended Offset Swan Neck Ring Spanners set includes 11 pieces with sizes ranging from 5/16in. The spanners are designed with a 12-point drive type and are made in the United Kingdom by the reputable brand Britool. These high-quality, durable spanners are perfect for automotive and workshop use, offering a versatile and essential addition to any tool collection. Double-ended offset (swan neck) ring spanners, primarily from the. These tools were manufactured in. And were commonly produced during the 1960s, 1970s, and 1980s. Spanner Identification and Details. The set includes various sizes, often marked with both. (Across Flats) measurements for SAE nuts and sometimes. Based on the visible markings and product information. Britool British Tool and Engineering Co. , a high-quality British brand known for its durable hand tools. 2RB Series, characterized by its deep offset or “swan neck” design, which allows for clearance in tight spaces. 94 A/F 15/16 2RB93100 100 A/F 1. 88 A/F 7/8 2RB8793 94 A/F 15/16. V 1/4 BS 3/16 W 2RB2852 5/16 BS 1/4 W. 75 A/F 3/4 2RB7587 88 A/F 7/8. 63 A/F 11/16 2RB6268 51 A/F 5/8. 52 A/F 9/16 2RB5062 63 A/F 11/16. 5/16 BS 1/4 W 2RB5260 3/8 BS 5/16 W. 3/8 BS 5/16 W 2RB4452 1/2 BS 7/16 W. 38 A/F 3/8 2RB3743 44 A/F 7/16. 31 A/F 5/16 2RB3137 38 A/F 3/8. 25 A/F 1/4 2RB2531 31 A/F 5/16.