In the period 1825-1851 medals were struck with the following specifications:
- Diameter: 35,55-35,75mm
- Text: "voor trouwen dienst"
- Thickness: 3,05-3,70mm
- Open/closed coat: closed
- Blocks in weaponshield: 16
- Mintmarking: none
- No shading between crown and schield
- signature: Simon F
Type 1 differs from other types since there is a "s" left down under the reverse (missing on type 2) and on the obverse there is an anchor left of the coat of arms (missing on very rare type 3).
(Ref: "Langdurige, eerlijke en trouwe dienst bij de Nederlandse Krijgsmacht; J.R. v.d. Neut; Hoorn; 2000; ISBN 90-9014307-6)