Solar accessories with a diameter of 3.5, control cabinet waterproof ring, nitrile rubber source manufacturer

Dimensions & Specifications
The diameter of 3.5 here needs to be defined in two commonly used nominal sizes to meet different installation requirements:
If the inner diameter is 3.5mm: It is suitable for 3.5mm outer diameter threading holes and terminals, with a common thickness of 1.5–3mm, ideal for sealing the circuit interfaces of small sensors.
If the inner diameter is 3.5cm (35mm): It is applicable for larger-caliber openings on the control cabinet panel (e.g., integrated interfaces for power cords and signal lines), with a thickness of 2–5mm. Thickened versions can be selected according to the pressure-bearing requirements of the cabinet.
The structure is mostly ring-shaped solid/hollow design, and some models are equipped with double-sided lips or groove clamping slots: the lip structure fits more tightly under pressure, while the slot type can be fixed on the edge of the cabinet opening to prevent displacement during installation or use.
Mainstream Materials
Weather-resistant silicone rubber (methyl vinyl silicone rubber) is preferred. For products used in harsh outdoor environments, fluororubber (FKM) is adopted.

High-grade Waterproof & Dustproof
Complies with IP65 and higher protection standards. When compressed, it can fully fill the gaps between the cabinet openings and pipe fittings/wiring, effectively blocking rainwater, dew and moisture from entering, and preventing short circuits and component corrosion inside the control cabinet.
Weather & Aging Resistance
It can withstand long-term outdoor UV radiation and alternating high and low temperatures (high temperatures from summer exposure, low temperatures and frost in winter). It is not prone to aging phenomena such as hardening, cracking or stickiness, with a service life of up to 3–5 years.
Insulation Safety
The silicone rubber material itself has excellent electrical insulation properties and does not conduct electricity. It can further improve the electrical safety factor of the control cabinet and avoid leakage risks caused by the material defects of sealing parts.
Easy Installation
Soft and elastic, it can be manually embedded into cabinet openings or fitted over wiring interfaces without special tools. The slot-type design enables direct snap-fit installation, preventing falling off after assembly.

Sealing of threading holes and wiring ports in grid-connected and off-grid solar photovoltaic control cabinets.
Waterproofing of sensor lines and power cord interfaces in control cabinets of solar water heating systems.
Sealing of outdoor interfaces in control boxes of solar street lamps and garden lamps.