The ISC D4 Work/Rescue Descender is a high-performance rope access and rescue device engineered for professionals who demand precision, control, and safety. Designed for ropes 10.5–11.5 mm in diameter, the D4 features a double-stop design with an auto-lock function and a panic brake, ensuring smooth operation under both normal and emergency conditions.

Constructed with a super hard stainless steel cam, the D4 is highly resistant to wear and corrosion, making it ideal for demanding rescue, work positioning, and rope access applications. Its innovative progressive cam action, where one cam operates inside another, provides smooth control at both slow and fast speeds, while allowing easy back-feeding for ascending or emergency hauling.

With a working load limit of 240 kg (529 lb) and compliance with CE, ANSI Z359.4, and NFPA standards, the D4 offers reliable performance for single or dual-user operations. Whether used for belay, hauling, or work positioning, the D4 descender delivers consistent, controlled performance in high-stakes environments.

Key Features:

• Double-stop auto-lock function and panic brake for safe operation
• Progressive cam design for controlled descents at variable speeds
• Stainless steel cam for exceptional wear and corrosion resistance
• Compatible with 10.5–11.5 mm (7/16") ropes
• Rated Working Load Limit: 240 kg (529 lb)
• Supports up to 2 persons simultaneously
• Easy back-feed capability for ascending or Z-rig emergency hauling
• Complies with CE EN 12841, ANSI Z359.4, NFPA 1983 standards
• Anodized finish for durability and long-lasting performance