Specifications:
The document provides technical specifications for two models of heavy-duty pneumatic toggle clamps, identified as 683-4 and 683-6. Key parameters include exerting force (F1), holding capacity (F3), applied force (Fi), air consumption per double stroke (Vn), angle, weight, and operating pressure.

Model 683-4:
- Exerting Force (F1): 1600 N
- Holding Capacity (F3): 5600 N
- Applied Force (Fi): 750 N
- Air Consumption (Vn): 1.28 dm³ at 6 bar
- Angle: 70°
- Weight: 4900 grams
- Operating Pressure: 6 bar

Model 683-6:
- Exerting Force (F1): 2000 N
- Holding Capacity (F3): 11000 N
- Applied Force (Fi): 1150 N
- Air Consumption (Vn): 2.5 dm³ at 6 bar
- Angle: 70°
- Weight: 8000 grams
- Operating Pressure: 6 bar

Dimensions:
The document lists detailed dimensions for each model, including measurements for various parts such as A, A2, B, B2, B3, B4, C, D, E, F, G, H, H2, J, K, L, M, N, X1, P, R, and piston diameter and stroke.

Model 683-4 Dimensions:
- Various dimensions are provided, such as A: 54 mm, B: 63 mm, and piston stroke: 80 mm.

Model 683-6 Dimensions:
- Various dimensions are provided, such as A: 70 mm, B: 74 mm, and piston stroke: 100 mm.

Features:
The pneumatic cylinders are described as double acting, magnetic, and cushioning, indicating advanced functionality for industrial applications.

Applications:
These clamps are suitable for heavy-duty applications, with a horizontal base and modular piston design, making them versatile for various industrial uses.