| Version | Year | Arm tube | Anti-skate | Knife Edge Bearings | Main Counterweight | Rider weight | Headshell |
|---|---|---|---|---|---|---|---|
| Series One | late 60’s or early 70’s | Stainless steel | No (available as optional) | Steel (housing has a round top) | Barrel-shaped (one piece) | One | Removable |
| Series Two | Until 1972 | Aluminum | Yes | Steel (housing with bishop mitre top) | Barrel-shaped (two pieces or one piece)* | Two** | Removable |
| 3012R | Post 1972 | Stainless steel | Yes | Nylon (steel as optional) (housing with bishop mitre top) | Barrel-shaped (two pieces )** | Two*** | Removable or Fixed |