G961 Vertical Extension Sleeve

The G961 Vertical Extension Sleeve is designed for use with the G960 Telescopic Under Floor Void Ventilator. Each extension sleeve enables a further two course brick adjustment vertically. Alternatively the sleeve can also be clipped to the base of the G960 to provide horizontal extension through larger cavities or wider internal blockwork: each unit extends the under floor ventilator a further 150 mm vertically or 185 mm horizontally and additional units can be added to achieve ventilation over any number of courses.

The G961 should be used in conjunction with other Manthorpe products to provide a complete through wall ventilation system.

General information

Uniclass 2015

Pr_30_59_96_92 Ventilation ductsPrimary


F30/17 Ventilation ducts in external walling

F30/171 Ventilation ducts in external walling

Specification data - Ventilation ducts

Product Reference

G961 Vertical Extension Sleeve

Standard product features



Size (l x w x h):

208.5 x 242 x 51.5 mm.

Free airflow:

7000 mm².

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